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Re: PE and PEMPro

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  • Lawrence
    Hello Brook My initial PE was 37 arc sec. After one PE correction from the three cycles, it was improved to 21 arc sec with Pempro but I am certain that I can
    Message 1 of 17 , Jun 1, 2006
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      Hello Brook

      My initial PE was 37 arc sec. After one PE correction from the three
      cycles, it was improved to 21 arc sec with Pempro but I am certain
      that I can re-do this and get a better result. I used an east - south
      - (slightly) west scan, believing that the so-called 'balanced drives'
      would eradicate the problem. I shall re-do using a west-only monitor.

      How many cycles did you use for the second (refined) measure?
      Presumably a different star?

      I am not sure what you mean by "Y drift in RA". Do you mean the
      successive drift downwards of the cycles? Also, did you use the image
      scale calibration wizard? I can never get more than one or two stars
      in this wizard. I prefer to use a plate solve.

      regards

      Lawrence Harris

      > From: "Brook Risner" jegerbekk@...
      > Subject: PE and PEMPro
      >
      >
      > I think I'm getting the hang of PEMpro and training the RCX mount. It looks
      > like I am approaching the advertised PE rate of less than 5 arcsec. PE
      > without PEC was initially >32 arcsec peak to peak. After building a curve
      > and loading to the mount I got that down to to about 7 arcsec. Built
      > another curve and refined the first and now it looks like about 5 arcsec
      > peak to peak. (My last session didn't get all the way through a full cycle
      > before trees block the view of my tracking stars, so I don't have full data
      > yet) I think I can refine it further and improve the PE even more. PEMPro
      > is the only way to go, in my humble opinion...
      >
      > I ended up changing the default tracking rate from Sidereal to Custom -2,
      > because PEMPro was showing Y drift in RA, but Dec didn't look like it was
      > drifting. I'm not sure why the tracking rate would be off just a bit, but
      > after I adjusted it, the curve was fairly linear.
      >
    • Michael
      Hi Brook and Jason, If I can just chime in here for a second regarding the PEMPro drift as well? I was concerned while doing an aquision because I noticed a
      Message 2 of 17 , Jun 1, 2006
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        Hi Brook and Jason,
        If I can just chime in here for a second regarding the PEMPro drift
        as well?
        I was concerned while doing an aquision because I noticed a very high
        degree of drift on my DEC axis as well... I couldn't figure it out.
        My manual drift alignment procedures kept a star centered on the DEC
        axis for 15-20 minutes before it moves a few arc seconds but the
        first 5 minutes of PEMPro data aquisition showed me almost 10 arc
        seconds of DEC (Y axis) drift.
        Why am I seeing this kind of drift when my scopes alignment appears
        to be so precise?
        Is this tracking modification Brook spoke of something I should
        consider changing as well?

        Best Regards,

        Michael


        --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@...> wrote:
        >
        > Thanks Jason.
        >
        > I think I did settle on 5th Order as well. I'll try the tip on
        using all
        > fundamentals, do you just use whole numbers, or do you go for some
        fractions
        > too?
        >
        > Changing the tracking rate was kind of a last resort. After I had
        gone
        > through the refine process and loaded the new curve to the scope I
        still had
        > "drift". I first set it to custom rate to -5 and that was too
        much as I
        > saw right away that the drift went in the other direction. I
        changed it to
        > -2 and voila, practically linear. I'll have to experiment with
        this some
        > more...
        >
        > BTW, what kind of PE are you able to obtain?
        >
        > Somehow I'm finding this fun...
        >
        > - Brook
        >
        >
        > On 5/31/06, galaxy_jason <jasone@...> wrote:
        > >
        > >
        > >
        > > you should not have to do any adjustments to the tracking rate.
        > > This may be caused by refraction. The software compensates for
        > > drift and assures that the correct number of counts are put into
        > > the table.
        > >
        > > I have had very good luck with changing the drift fitting to
        > > a something other than linear, like 5th order. Also turn on
        > > ALL fundementals 1-40 or so. This takes a LONG time to build
        > > a PE curve but it will follow the wiggles of the high order
        > > gears. Overall magnitude of the PE is less of a concern than
        > > the sort arc-second/second errors.
        > >
        > > -Jason Ware
        > > http://www.galaxyphoto.com
        > >
        > > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@> wrote:
        > > >
        > > > I think I'm getting the hang of PEMpro and training the RCX
        mount.
        > > It looks
        > > > like I am approaching the advertised PE rate of less than 5
        > > arcsec. PE
        > > > without PEC was initially >32 arcsec peak to peak. After
        building
        > > a curve
        > > > and loading to the mount I got that down to to about 7 arcsec.
        > > Built
        > > > another curve and refined the first and now it looks like about
        5
        > > arcsec
        > > > peak to peak. (My last session didn't get all the way through a
        > > full cycle
        > > > before trees block the view of my tracking stars, so I don't
        have
        > > full data
        > > > yet) I think I can refine it further and improve the PE even
        > > more. PEMPro
        > > > is the only way to go, in my humble opinion...
        > > >
        > > > I ended up changing the default tracking rate from Sidereal to
        > > Custom -2,
        > > > because PEMPro was showing Y drift in RA, but Dec didn't look
        like
        > > it was
        > > > drifting. I'm not sure why the tracking rate would be off just
        a
        > > bit, but
        > > > after I adjusted it, the curve was fairly linear.
        > > >
        > > > I've included a link to some screen shots for reference.
        > > >
        > > > http://home.earthlink.net/~jegerbekk/PE%20Results.JPG
        > > >
        > > > I would appreciate any comments or to hear of results others are
        > > getting.
        > > >
        > > > Thanks,
        > > > Brook
        > > >
        > >
        > >
        > >
        > >
        > >
        > >
        > >
        > >
        > >
        > >
        > >
        > >
        > > Yahoo! Groups Links
        > >
        > >
        > >
        > >
        > >
        > >
        > >
        >
      • Ray Gralak
        Hi Michael, PEMPro is very sensitive measurement tool. ONE diameter of the star visually or on a CCD is a few arc-seconds. If you are seeing the star move a
        Message 3 of 17 , Jun 1, 2006
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          Hi Michael,

          PEMPro is very sensitive measurement tool. ONE diameter of the star
          visually or on a CCD is a few arc-seconds. If you are seeing the star
          move a few stellar diameters in 5 minutes that is about 10
          arc-seconds.

          To confirm this try taking an exposure for 20 minutes and measure the
          stellar trails that result.

          -Ray

          > -----Original Message-----
          > From: RCX400@yahoogroups.com [mailto:RCX400@yahoogroups.com]
          > On Behalf Of Michael
          > Sent: Thursday, June 01, 2006 7:26 AM
          > To: RCX400@yahoogroups.com
          > Subject: [RCX400] Re: PE and PEMPro
          >
          > Hi Brook and Jason,
          > If I can just chime in here for a second regarding the PEMPro drift
          > as well?
          > I was concerned while doing an aquision because I noticed a very
          high
          > degree of drift on my DEC axis as well... I couldn't figure it out.
          > My manual drift alignment procedures kept a star centered on the DEC

          > axis for 15-20 minutes before it moves a few arc seconds but the
          > first 5 minutes of PEMPro data aquisition showed me almost 10 arc
          > seconds of DEC (Y axis) drift.
          > Why am I seeing this kind of drift when my scopes alignment appears
          > to be so precise?
          > Is this tracking modification Brook spoke of something I should
          > consider changing as well?
          >
          > Best Regards,
          >
          > Michael
          >
          >
          > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@...> wrote:
          > >
          > > Thanks Jason.
          > >
          > > I think I did settle on 5th Order as well. I'll try the tip on
          > using all
          > > fundamentals, do you just use whole numbers, or do you go for some

          > fractions
          > > too?
          > >
          > > Changing the tracking rate was kind of a last resort. After I had

          > gone
          > > through the refine process and loaded the new curve to the scope I

          > still had
          > > "drift". I first set it to custom rate to -5 and that was too
          > much as I
          > > saw right away that the drift went in the other direction. I
          > changed it to
          > > -2 and voila, practically linear. I'll have to experiment with
          > this some
          > > more...
          > >
          > > BTW, what kind of PE are you able to obtain?
          > >
          > > Somehow I'm finding this fun...
          > >
          > > - Brook
          > >
          > >
          > > On 5/31/06, galaxy_jason <jasone@...> wrote:
          > > >
          > > >
          > > >
          > > > you should not have to do any adjustments to the tracking rate.
          > > > This may be caused by refraction. The software compensates for
          > > > drift and assures that the correct number of counts are put into
          > > > the table.
          > > >
          > > > I have had very good luck with changing the drift fitting to
          > > > a something other than linear, like 5th order. Also turn on
          > > > ALL fundementals 1-40 or so. This takes a LONG time to build
          > > > a PE curve but it will follow the wiggles of the high order
          > > > gears. Overall magnitude of the PE is less of a concern than
          > > > the sort arc-second/second errors.
          > > >
          > > > -Jason Ware
          > > > http://www.galaxyphoto.com
          > > >
          > > > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@>
          wrote:
          > > > >
          > > > > I think I'm getting the hang of PEMpro and training the RCX
          > mount.
          > > > It looks
          > > > > like I am approaching the advertised PE rate of less than 5
          > > > arcsec. PE
          > > > > without PEC was initially >32 arcsec peak to peak. After
          > building
          > > > a curve
          > > > > and loading to the mount I got that down to to about 7 arcsec.
          > > > Built
          > > > > another curve and refined the first and now it looks like
          about
          > 5
          > > > arcsec
          > > > > peak to peak. (My last session didn't get all the way through
          a
          > > > full cycle
          > > > > before trees block the view of my tracking stars, so I don't
          > have
          > > > full data
          > > > > yet) I think I can refine it further and improve the PE even
          > > > more. PEMPro
          > > > > is the only way to go, in my humble opinion...
          > > > >
          > > > > I ended up changing the default tracking rate from Sidereal to
          > > > Custom -2,
          > > > > because PEMPro was showing Y drift in RA, but Dec didn't look
          > like
          > > > it was
          > > > > drifting. I'm not sure why the tracking rate would be off
          just
          > a
          > > > bit, but
          > > > > after I adjusted it, the curve was fairly linear.
          > > > >
          > > > > I've included a link to some screen shots for reference.
          > > > >
          > > > > http://home.earthlink.net/~jegerbekk/PE%20Results.JPG
          > > > >
          > > > > I would appreciate any comments or to hear of results others
          are
          > > > getting.
          > > > >
          > > > > Thanks,
          > > > > Brook
          > > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > > Yahoo! Groups Links
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > >
          >
          >
          >
          >
          >
          >
          >
          >
          >
          >
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        • Brook Risner
          Hi Lawernce, I used three cycles for the initial curve and two cycles for the second refine curve. I d like to do a couple more cycles and refine the current
          Message 4 of 17 , Jun 1, 2006
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            Hi Lawernce,
             
            I used three cycles for the initial curve and two cycles for the second refine curve.  I'd like to do a couple more cycles and refine the current curve one more time to see how good I can make it.  Then, I may try to re-work my original three cycle curve and add different refine curves to see if I can improve things any. 
             
            I only used one star, during one continuous viewing session, for my cycles and analysis (just west of the meridian at close to 0 degrees dec - "green" in the calibration wizard).  It will be interesting to see how other parts of the sky, east of meridian for example, test out.
             
            I was able to find a FOV with 3 stars to do my calibration with.  A very hard task with a small CCD (Meade DSI Pro II) and the 12" RCX at F8...
             
            In regards top the "Y drift in RA", I am referring to the successive, in my case upward, drift while acquiring data.  The Dec drift is not nearly as much as the drift in RA, that's why I referred to it as "Y drift in RA". 
             
            Thanks,
            Brook
             
             
             
             

             
            On 6/1/06, Lawrence <lawrence@...
            > wrote:
            Hello Brook

            My initial PE was 37 arc sec.  After one PE correction from the three
            cycles, it was improved to 21 arc sec with Pempro but I am certain
            that I can re-do this and get a better result.  I used an east - south
            - (slightly) west scan, believing that the so-called 'balanced drives'
            would eradicate the problem.  I shall re-do using a west-only monitor.

            How many cycles did you use for the second (refined) measure?
            Presumably a different star?

            I am not sure what you mean by "Y drift in RA".  Do you mean the
            successive drift downwards of the cycles?  Also, did you use the image
            scale calibration wizard?  I can never get more than one or two stars
            in this wizard.  I prefer to use a plate solve.

            regards

            Lawrence Harris

          • Brook Risner
            Hi Michael, I m far from an expert and really not very experienced with this, but I was asking myself the same question you are asking. I finally decided to
            Message 5 of 17 , Jun 1, 2006
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              Hi Michael,
               
              I'm far from an expert and really not very experienced with this, but I was asking myself the same question you are asking.  I finally decided to change the tracking rate because of the case study for an RCX400 in the PEMPro help files.  It states "There is also substantial drift in Right Ascension which may be the result of mis-polar alignment, an imperfect tracking rate, or mount/OTA flexure."  I think my polar alignment is pretty good and I don't think that I have mount or OTA flexure.  That left me with an imperfect tracking rate.  Based on that, I started adjusting the custom rate and it looks like it helped.
               
              I'm toying around with the idea of changing the tracking rate enough so that PEC only has to make corrections in one direction.  Similar to how I hear people do it for Dec autoguiding.  It will be interesting to see results from a test like that compared to normal PEC training...
               
              Although, I probably should move on and actually start trying to image something :-)
               
              - Brook

               
              On 6/1/06, Michael <mrscheider@...> wrote:
              Hi Brook and Jason,
              If I can just chime in here for a second regarding the PEMPro drift
              as well?
              I was concerned while doing an aquision because I noticed a very high
              degree of drift on my DEC axis as well... I couldn't figure it out.
              My manual drift alignment procedures kept a star centered on the DEC
              axis for 15-20 minutes before it moves a few arc seconds but the
              first 5 minutes of PEMPro data aquisition showed me almost 10 arc
              seconds of DEC (Y axis) drift.
              Why am I seeing this kind of drift when my scopes alignment appears
              to be so precise?
              Is this tracking modification Brook spoke of something I should
              consider changing as well?

              Best Regards,

              Michael
            • galaxy_jason
              Was the CCD attached when you were doing the dec drift? Were you doing the manual drift in the same part of the sky as the PEMpro run? Changing the instrument
              Message 6 of 17 , Jun 1, 2006
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                Was the CCD attached when you were doing the dec drift? Were
                you doing the manual drift in the same part of the sky as
                the PEMpro run?

                Changing the instrument package or slewing to a different
                part of the sky is enough to change the alignment slightly
                due to mount flexure.


                --- In RCX400@yahoogroups.com, "Michael" <mrscheider@...> wrote:
                >
                > Hi Brook and Jason,
                > If I can just chime in here for a second regarding the PEMPro drift
                > as well?
                > I was concerned while doing an aquision because I noticed a very
                high
                > degree of drift on my DEC axis as well... I couldn't figure it out.
                > My manual drift alignment procedures kept a star centered on the
                DEC
                > axis for 15-20 minutes before it moves a few arc seconds but the
                > first 5 minutes of PEMPro data aquisition showed me almost 10 arc
                > seconds of DEC (Y axis) drift.
                > Why am I seeing this kind of drift when my scopes alignment appears
                > to be so precise?
                > Is this tracking modification Brook spoke of something I should
                > consider changing as well?
                >
                > Best Regards,
                >
                > Michael
                >
                >
                > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@> wrote:
                > >
                > > Thanks Jason.
                > >
                > > I think I did settle on 5th Order as well. I'll try the tip on
                > using all
                > > fundamentals, do you just use whole numbers, or do you go for
                some
                > fractions
                > > too?
                > >
                > > Changing the tracking rate was kind of a last resort. After I
                had
                > gone
                > > through the refine process and loaded the new curve to the scope
                I
                > still had
                > > "drift". I first set it to custom rate to -5 and that was too
                > much as I
                > > saw right away that the drift went in the other direction. I
                > changed it to
                > > -2 and voila, practically linear. I'll have to experiment with
                > this some
                > > more...
                > >
                > > BTW, what kind of PE are you able to obtain?
                > >
                > > Somehow I'm finding this fun...
                > >
                > > - Brook
                > >
                > >
                > > On 5/31/06, galaxy_jason <jasone@> wrote:
                > > >
                > > >
                > > >
                > > > you should not have to do any adjustments to the tracking rate.
                > > > This may be caused by refraction. The software compensates for
                > > > drift and assures that the correct number of counts are put into
                > > > the table.
                > > >
                > > > I have had very good luck with changing the drift fitting to
                > > > a something other than linear, like 5th order. Also turn on
                > > > ALL fundementals 1-40 or so. This takes a LONG time to build
                > > > a PE curve but it will follow the wiggles of the high order
                > > > gears. Overall magnitude of the PE is less of a concern than
                > > > the sort arc-second/second errors.
                > > >
                > > > -Jason Ware
                > > > http://www.galaxyphoto.com
                > > >
                > > > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@>
                wrote:
                > > > >
                > > > > I think I'm getting the hang of PEMpro and training the RCX
                > mount.
                > > > It looks
                > > > > like I am approaching the advertised PE rate of less than 5
                > > > arcsec. PE
                > > > > without PEC was initially >32 arcsec peak to peak. After
                > building
                > > > a curve
                > > > > and loading to the mount I got that down to to about 7 arcsec.
                > > > Built
                > > > > another curve and refined the first and now it looks like
                about
                > 5
                > > > arcsec
                > > > > peak to peak. (My last session didn't get all the way
                through a
                > > > full cycle
                > > > > before trees block the view of my tracking stars, so I don't
                > have
                > > > full data
                > > > > yet) I think I can refine it further and improve the PE even
                > > > more. PEMPro
                > > > > is the only way to go, in my humble opinion...
                > > > >
                > > > > I ended up changing the default tracking rate from Sidereal to
                > > > Custom -2,
                > > > > because PEMPro was showing Y drift in RA, but Dec didn't look
                > like
                > > > it was
                > > > > drifting. I'm not sure why the tracking rate would be off
                just
                > a
                > > > bit, but
                > > > > after I adjusted it, the curve was fairly linear.
                > > > >
                > > > > I've included a link to some screen shots for reference.
                > > > >
                > > > > http://home.earthlink.net/~jegerbekk/PE%20Results.JPG
                > > > >
                > > > > I would appreciate any comments or to hear of results others
                are
                > > > getting.
                > > > >
                > > > > Thanks,
                > > > > Brook
                > > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > > Yahoo! Groups Links
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > >
                >
              • Michael
                To be honest, I have a little of what Brooks got... this new obsession with PEMPro to produce the best PE possible on my RCX. When I initially used the
                Message 7 of 17 , Jun 1, 2006
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                  To be honest, I have a little of what Brooks got... this new
                  obsession with PEMPro to produce the best PE possible on my RCX.
                  When I initially used the software, I was surprised at the unusually
                  low PE it had from the beginning. I think it was because of Dr. Clays
                  work on the scope, PE peak 2 peak was <21 sec.
                  But I noticed too that the DEC drift was off.. Brook, I saw that same
                  refinement article on the RCX and saw that my DEC drift was worse
                  than what was in that article and he called HIS substantial! That's
                  where I got hooked on the PEMPro data.
                  I began a 3 day campaign on achieving the best polar alignment
                  possible with what I had. I figured if the PE was that low, imagine
                  when the alignment was right on!
                  Well, I drifted it with a 4mm reticle (9mm w/ barlow) until I noticed
                  no drift for 15-20 minutes.
                  Then I drifted with the ST2k at F8 until again, no drift for 15-20
                  minutes, actually, while doing the east/west, I didn't get any drift
                  until after 25 minutes.
                  I began acquiring data on PEMPro in the same area of sky I began e/w
                  drifting so flexure of any component would have been the same.
                  The first 5 minutes of PEMPro data shows 10 seconds of +DEC drift.


                  --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@...> wrote:
                  >
                  >
                  > Was the CCD attached when you were doing the dec drift? Were
                  > you doing the manual drift in the same part of the sky as
                  > the PEMpro run?
                  >
                  > Changing the instrument package or slewing to a different
                  > part of the sky is enough to change the alignment slightly
                  > due to mount flexure.
                  >
                  >
                  > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@> wrote:
                  > >
                  > > Hi Brook and Jason,
                  > > If I can just chime in here for a second regarding the PEMPro
                  drift
                  > > as well?
                  > > I was concerned while doing an aquision because I noticed a very
                  > high
                  > > degree of drift on my DEC axis as well... I couldn't figure it
                  out.
                  > > My manual drift alignment procedures kept a star centered on the
                  > DEC
                  > > axis for 15-20 minutes before it moves a few arc seconds but the
                  > > first 5 minutes of PEMPro data aquisition showed me almost 10 arc
                  > > seconds of DEC (Y axis) drift.
                  > > Why am I seeing this kind of drift when my scopes alignment
                  appears
                  > > to be so precise?
                  > > Is this tracking modification Brook spoke of something I should
                  > > consider changing as well?
                  > >
                  > > Best Regards,
                  > >
                  > > Michael
                  > >
                  > >
                  > > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@> wrote:
                  > > >
                  > > > Thanks Jason.
                  > > >
                  > > > I think I did settle on 5th Order as well. I'll try the tip on
                  > > using all
                  > > > fundamentals, do you just use whole numbers, or do you go for
                  > some
                  > > fractions
                  > > > too?
                  > > >
                  > > > Changing the tracking rate was kind of a last resort. After I
                  > had
                  > > gone
                  > > > through the refine process and loaded the new curve to the
                  scope
                  > I
                  > > still had
                  > > > "drift". I first set it to custom rate to -5 and that was too
                  > > much as I
                  > > > saw right away that the drift went in the other direction. I
                  > > changed it to
                  > > > -2 and voila, practically linear. I'll have to experiment with
                  > > this some
                  > > > more...
                  > > >
                  > > > BTW, what kind of PE are you able to obtain?
                  > > >
                  > > > Somehow I'm finding this fun...
                  > > >
                  > > > - Brook
                  > > >
                  > > >
                  > > > On 5/31/06, galaxy_jason <jasone@> wrote:
                  > > > >
                  > > > >
                  > > > >
                  > > > > you should not have to do any adjustments to the tracking
                  rate.
                  > > > > This may be caused by refraction. The software compensates for
                  > > > > drift and assures that the correct number of counts are put
                  into
                  > > > > the table.
                  > > > >
                  > > > > I have had very good luck with changing the drift fitting to
                  > > > > a something other than linear, like 5th order. Also turn on
                  > > > > ALL fundementals 1-40 or so. This takes a LONG time to build
                  > > > > a PE curve but it will follow the wiggles of the high order
                  > > > > gears. Overall magnitude of the PE is less of a concern than
                  > > > > the sort arc-second/second errors.
                  > > > >
                  > > > > -Jason Ware
                  > > > > http://www.galaxyphoto.com
                  > > > >
                  > > > > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@>
                  > wrote:
                  > > > > >
                  > > > > > I think I'm getting the hang of PEMpro and training the RCX
                  > > mount.
                  > > > > It looks
                  > > > > > like I am approaching the advertised PE rate of less than 5
                  > > > > arcsec. PE
                  > > > > > without PEC was initially >32 arcsec peak to peak. After
                  > > building
                  > > > > a curve
                  > > > > > and loading to the mount I got that down to to about 7
                  arcsec.
                  > > > > Built
                  > > > > > another curve and refined the first and now it looks like
                  > about
                  > > 5
                  > > > > arcsec
                  > > > > > peak to peak. (My last session didn't get all the way
                  > through a
                  > > > > full cycle
                  > > > > > before trees block the view of my tracking stars, so I
                  don't
                  > > have
                  > > > > full data
                  > > > > > yet) I think I can refine it further and improve the PE
                  even
                  > > > > more. PEMPro
                  > > > > > is the only way to go, in my humble opinion...
                  > > > > >
                  > > > > > I ended up changing the default tracking rate from Sidereal
                  to
                  > > > > Custom -2,
                  > > > > > because PEMPro was showing Y drift in RA, but Dec didn't
                  look
                  > > like
                  > > > > it was
                  > > > > > drifting. I'm not sure why the tracking rate would be off
                  > just
                  > > a
                  > > > > bit, but
                  > > > > > after I adjusted it, the curve was fairly linear.
                  > > > > >
                  > > > > > I've included a link to some screen shots for reference.
                  > > > > >
                  > > > > > http://home.earthlink.net/~jegerbekk/PE%20Results.JPG
                  > > > > >
                  > > > > > I would appreciate any comments or to hear of results
                  others
                  > are
                  > > > > getting.
                  > > > > >
                  > > > > > Thanks,
                  > > > > > Brook
                  > > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > > Yahoo! Groups Links
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > >
                  > >
                  >
                • galaxy_jason
                  Here is a simple test. Instead of pempro, just take a series of exposures in MaxIm and see if the star drifts in dec. ... unusually ... Clays ... same ...
                  Message 8 of 17 , Jun 1, 2006
                  • 0 Attachment
                    Here is a simple test. Instead of pempro, just take a series
                    of exposures in MaxIm and see if the star drifts in dec.

                    --- In RCX400@yahoogroups.com, "Michael" <mrscheider@...> wrote:
                    >
                    > To be honest, I have a little of what Brooks got... this new
                    > obsession with PEMPro to produce the best PE possible on my RCX.
                    > When I initially used the software, I was surprised at the
                    unusually
                    > low PE it had from the beginning. I think it was because of Dr.
                    Clays
                    > work on the scope, PE peak 2 peak was <21 sec.
                    > But I noticed too that the DEC drift was off.. Brook, I saw that
                    same
                    > refinement article on the RCX and saw that my DEC drift was worse
                    > than what was in that article and he called HIS substantial!
                    That's
                    > where I got hooked on the PEMPro data.
                    > I began a 3 day campaign on achieving the best polar alignment
                    > possible with what I had. I figured if the PE was that low,
                    imagine
                    > when the alignment was right on!
                    > Well, I drifted it with a 4mm reticle (9mm w/ barlow) until I
                    noticed
                    > no drift for 15-20 minutes.
                    > Then I drifted with the ST2k at F8 until again, no drift for 15-20
                    > minutes, actually, while doing the east/west, I didn't get any
                    drift
                    > until after 25 minutes.
                    > I began acquiring data on PEMPro in the same area of sky I began
                    e/w
                    > drifting so flexure of any component would have been the same.
                    > The first 5 minutes of PEMPro data shows 10 seconds of +DEC drift.
                    >
                    >
                    > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@> wrote:
                    > >
                    > >
                    > > Was the CCD attached when you were doing the dec drift? Were
                    > > you doing the manual drift in the same part of the sky as
                    > > the PEMpro run?
                    > >
                    > > Changing the instrument package or slewing to a different
                    > > part of the sky is enough to change the alignment slightly
                    > > due to mount flexure.
                    > >
                    > >
                    > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@> wrote:
                    > > >
                    > > > Hi Brook and Jason,
                    > > > If I can just chime in here for a second regarding the PEMPro
                    > drift
                    > > > as well?
                    > > > I was concerned while doing an aquision because I noticed a
                    very
                    > > high
                    > > > degree of drift on my DEC axis as well... I couldn't figure it
                    > out.
                    > > > My manual drift alignment procedures kept a star centered on
                    the
                    > > DEC
                    > > > axis for 15-20 minutes before it moves a few arc seconds but
                    the
                    > > > first 5 minutes of PEMPro data aquisition showed me almost 10
                    arc
                    > > > seconds of DEC (Y axis) drift.
                    > > > Why am I seeing this kind of drift when my scopes alignment
                    > appears
                    > > > to be so precise?
                    > > > Is this tracking modification Brook spoke of something I
                    should
                    > > > consider changing as well?
                    > > >
                    > > > Best Regards,
                    > > >
                    > > > Michael
                    > > >
                    > > >
                    > > > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@>
                    wrote:
                    > > > >
                    > > > > Thanks Jason.
                    > > > >
                    > > > > I think I did settle on 5th Order as well. I'll try the tip
                    on
                    > > > using all
                    > > > > fundamentals, do you just use whole numbers, or do you go
                    for
                    > > some
                    > > > fractions
                    > > > > too?
                    > > > >
                    > > > > Changing the tracking rate was kind of a last resort. After
                    I
                    > > had
                    > > > gone
                    > > > > through the refine process and loaded the new curve to the
                    > scope
                    > > I
                    > > > still had
                    > > > > "drift". I first set it to custom rate to -5 and that was
                    too
                    > > > much as I
                    > > > > saw right away that the drift went in the other direction.
                    I
                    > > > changed it to
                    > > > > -2 and voila, practically linear. I'll have to experiment
                    with
                    > > > this some
                    > > > > more...
                    > > > >
                    > > > > BTW, what kind of PE are you able to obtain?
                    > > > >
                    > > > > Somehow I'm finding this fun...
                    > > > >
                    > > > > - Brook
                    > > > >
                    > > > >
                    > > > > On 5/31/06, galaxy_jason <jasone@> wrote:
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > > you should not have to do any adjustments to the tracking
                    > rate.
                    > > > > > This may be caused by refraction. The software compensates
                    for
                    > > > > > drift and assures that the correct number of counts are
                    put
                    > into
                    > > > > > the table.
                    > > > > >
                    > > > > > I have had very good luck with changing the drift fitting
                    to
                    > > > > > a something other than linear, like 5th order. Also turn on
                    > > > > > ALL fundementals 1-40 or so. This takes a LONG time to
                    build
                    > > > > > a PE curve but it will follow the wiggles of the high order
                    > > > > > gears. Overall magnitude of the PE is less of a concern
                    than
                    > > > > > the sort arc-second/second errors.
                    > > > > >
                    > > > > > -Jason Ware
                    > > > > > http://www.galaxyphoto.com
                    > > > > >
                    > > > > > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@>
                    > > wrote:
                    > > > > > >
                    > > > > > > I think I'm getting the hang of PEMpro and training the
                    RCX
                    > > > mount.
                    > > > > > It looks
                    > > > > > > like I am approaching the advertised PE rate of less
                    than 5
                    > > > > > arcsec. PE
                    > > > > > > without PEC was initially >32 arcsec peak to peak.
                    After
                    > > > building
                    > > > > > a curve
                    > > > > > > and loading to the mount I got that down to to about 7
                    > arcsec.
                    > > > > > Built
                    > > > > > > another curve and refined the first and now it looks
                    like
                    > > about
                    > > > 5
                    > > > > > arcsec
                    > > > > > > peak to peak. (My last session didn't get all the way
                    > > through a
                    > > > > > full cycle
                    > > > > > > before trees block the view of my tracking stars, so I
                    > don't
                    > > > have
                    > > > > > full data
                    > > > > > > yet) I think I can refine it further and improve the PE
                    > even
                    > > > > > more. PEMPro
                    > > > > > > is the only way to go, in my humble opinion...
                    > > > > > >
                    > > > > > > I ended up changing the default tracking rate from
                    Sidereal
                    > to
                    > > > > > Custom -2,
                    > > > > > > because PEMPro was showing Y drift in RA, but Dec didn't
                    > look
                    > > > like
                    > > > > > it was
                    > > > > > > drifting. I'm not sure why the tracking rate would be
                    off
                    > > just
                    > > > a
                    > > > > > bit, but
                    > > > > > > after I adjusted it, the curve was fairly linear.
                    > > > > > >
                    > > > > > > I've included a link to some screen shots for reference.
                    > > > > > >
                    > > > > > > http://home.earthlink.net/~jegerbekk/PE%20Results.JPG
                    > > > > > >
                    > > > > > > I would appreciate any comments or to hear of results
                    > others
                    > > are
                    > > > > > getting.
                    > > > > > >
                    > > > > > > Thanks,
                    > > > > > > Brook
                    > > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > > Yahoo! Groups Links
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > >
                    > > >
                    > >
                    >
                  • Michael
                    Hi Jason, Well, Like I said, I drift aligned the scope with the CCD and Maxim DL for nearly 25 minutes until I noticed drift. That was unguided. Of course the
                    Message 9 of 17 , Jun 2, 2006
                    • 0 Attachment
                      Hi Jason,

                      Well, Like I said, I drift aligned the scope with the CCD and Maxim
                      DL for nearly 25 minutes until I noticed drift. That was unguided. Of
                      course the RA was all over the place with PE turned off but the star
                      doesn't drift within 5-10 minutes time.
                      That's why I am asking why PEMPro shows drift?
                      Could it be the tracking rate, same as Brooks problem?

                      Thanks,

                      Michael

                      --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@...> wrote:
                      >
                      >
                      >
                      > Here is a simple test. Instead of pempro, just take a series
                      > of exposures in MaxIm and see if the star drifts in dec.
                      >
                      > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@> wrote:
                      > >
                      > > To be honest, I have a little of what Brooks got... this new
                      > > obsession with PEMPro to produce the best PE possible on my RCX.
                      > > When I initially used the software, I was surprised at the
                      > unusually
                      > > low PE it had from the beginning. I think it was because of Dr.
                      > Clays
                      > > work on the scope, PE peak 2 peak was <21 sec.
                      > > But I noticed too that the DEC drift was off.. Brook, I saw that
                      > same
                      > > refinement article on the RCX and saw that my DEC drift was worse
                      > > than what was in that article and he called HIS substantial!
                      > That's
                      > > where I got hooked on the PEMPro data.
                      > > I began a 3 day campaign on achieving the best polar alignment
                      > > possible with what I had. I figured if the PE was that low,
                      > imagine
                      > > when the alignment was right on!
                      > > Well, I drifted it with a 4mm reticle (9mm w/ barlow) until I
                      > noticed
                      > > no drift for 15-20 minutes.
                      > > Then I drifted with the ST2k at F8 until again, no drift for 15-
                      20
                      > > minutes, actually, while doing the east/west, I didn't get any
                      > drift
                      > > until after 25 minutes.
                      > > I began acquiring data on PEMPro in the same area of sky I began
                      > e/w
                      > > drifting so flexure of any component would have been the same.
                      > > The first 5 minutes of PEMPro data shows 10 seconds of +DEC
                      drift.
                      > >
                      > >
                      > > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@> wrote:
                      > > >
                      > > >
                      > > > Was the CCD attached when you were doing the dec drift? Were
                      > > > you doing the manual drift in the same part of the sky as
                      > > > the PEMpro run?
                      > > >
                      > > > Changing the instrument package or slewing to a different
                      > > > part of the sky is enough to change the alignment slightly
                      > > > due to mount flexure.
                      > > >
                      > > >
                      > > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@> wrote:
                      > > > >
                      > > > > Hi Brook and Jason,
                      > > > > If I can just chime in here for a second regarding the PEMPro
                      > > drift
                      > > > > as well?
                      > > > > I was concerned while doing an aquision because I noticed a
                      > very
                      > > > high
                      > > > > degree of drift on my DEC axis as well... I couldn't figure
                      it
                      > > out.
                      > > > > My manual drift alignment procedures kept a star centered on
                      > the
                      > > > DEC
                      > > > > axis for 15-20 minutes before it moves a few arc seconds but
                      > the
                      > > > > first 5 minutes of PEMPro data aquisition showed me almost 10
                      > arc
                      > > > > seconds of DEC (Y axis) drift.
                      > > > > Why am I seeing this kind of drift when my scopes alignment
                      > > appears
                      > > > > to be so precise?
                      > > > > Is this tracking modification Brook spoke of something I
                      > should
                      > > > > consider changing as well?
                      > > > >
                      > > > > Best Regards,
                      > > > >
                      > > > > Michael
                      > > > >
                      > > > >
                      > > > > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@>
                      > wrote:
                      > > > > >
                      > > > > > Thanks Jason.
                      > > > > >
                      > > > > > I think I did settle on 5th Order as well. I'll try the
                      tip
                      > on
                      > > > > using all
                      > > > > > fundamentals, do you just use whole numbers, or do you go
                      > for
                      > > > some
                      > > > > fractions
                      > > > > > too?
                      > > > > >
                      > > > > > Changing the tracking rate was kind of a last resort.
                      After
                      > I
                      > > > had
                      > > > > gone
                      > > > > > through the refine process and loaded the new curve to the
                      > > scope
                      > > > I
                      > > > > still had
                      > > > > > "drift". I first set it to custom rate to -5 and that was
                      > too
                      > > > > much as I
                      > > > > > saw right away that the drift went in the other direction.
                      > I
                      > > > > changed it to
                      > > > > > -2 and voila, practically linear. I'll have to experiment
                      > with
                      > > > > this some
                      > > > > > more...
                      > > > > >
                      > > > > > BTW, what kind of PE are you able to obtain?
                      > > > > >
                      > > > > > Somehow I'm finding this fun...
                      > > > > >
                      > > > > > - Brook
                      > > > > >
                      > > > > >
                      > > > > > On 5/31/06, galaxy_jason <jasone@> wrote:
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > > you should not have to do any adjustments to the tracking
                      > > rate.
                      > > > > > > This may be caused by refraction. The software
                      compensates
                      > for
                      > > > > > > drift and assures that the correct number of counts are
                      > put
                      > > into
                      > > > > > > the table.
                      > > > > > >
                      > > > > > > I have had very good luck with changing the drift fitting
                      > to
                      > > > > > > a something other than linear, like 5th order. Also turn
                      on
                      > > > > > > ALL fundementals 1-40 or so. This takes a LONG time to
                      > build
                      > > > > > > a PE curve but it will follow the wiggles of the high
                      order
                      > > > > > > gears. Overall magnitude of the PE is less of a concern
                      > than
                      > > > > > > the sort arc-second/second errors.
                      > > > > > >
                      > > > > > > -Jason Ware
                      > > > > > > http://www.galaxyphoto.com
                      > > > > > >
                      > > > > > > --- In RCX400@yahoogroups.com, "Brook Risner"
                      <jegerbekk@>
                      > > > wrote:
                      > > > > > > >
                      > > > > > > > I think I'm getting the hang of PEMpro and training the
                      > RCX
                      > > > > mount.
                      > > > > > > It looks
                      > > > > > > > like I am approaching the advertised PE rate of less
                      > than 5
                      > > > > > > arcsec. PE
                      > > > > > > > without PEC was initially >32 arcsec peak to peak.
                      > After
                      > > > > building
                      > > > > > > a curve
                      > > > > > > > and loading to the mount I got that down to to about 7
                      > > arcsec.
                      > > > > > > Built
                      > > > > > > > another curve and refined the first and now it looks
                      > like
                      > > > about
                      > > > > 5
                      > > > > > > arcsec
                      > > > > > > > peak to peak. (My last session didn't get all the way
                      > > > through a
                      > > > > > > full cycle
                      > > > > > > > before trees block the view of my tracking stars, so I
                      > > don't
                      > > > > have
                      > > > > > > full data
                      > > > > > > > yet) I think I can refine it further and improve the
                      PE
                      > > even
                      > > > > > > more. PEMPro
                      > > > > > > > is the only way to go, in my humble opinion...
                      > > > > > > >
                      > > > > > > > I ended up changing the default tracking rate from
                      > Sidereal
                      > > to
                      > > > > > > Custom -2,
                      > > > > > > > because PEMPro was showing Y drift in RA, but Dec
                      didn't
                      > > look
                      > > > > like
                      > > > > > > it was
                      > > > > > > > drifting. I'm not sure why the tracking rate would be
                      > off
                      > > > just
                      > > > > a
                      > > > > > > bit, but
                      > > > > > > > after I adjusted it, the curve was fairly linear.
                      > > > > > > >
                      > > > > > > > I've included a link to some screen shots for reference.
                      > > > > > > >
                      > > > > > > > http://home.earthlink.net/~jegerbekk/PE%20Results.JPG
                      > > > > > > >
                      > > > > > > > I would appreciate any comments or to hear of results
                      > > others
                      > > > are
                      > > > > > > getting.
                      > > > > > > >
                      > > > > > > > Thanks,
                      > > > > > > > Brook
                      > > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > > Yahoo! Groups Links
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > > >
                      > > > > >
                      > > > >
                      > > >
                      > >
                      >
                    • Ray Gralak
                      Hi Michael, Dec never moves so it cannot be tracking! It is probably polar misalignment but other things such as refraction and mount/OTA flexure will (not
                      Message 10 of 17 , Jun 2, 2006
                      • 0 Attachment
                        Hi Michael,

                        Dec never moves so it cannot be tracking! It is probably polar
                        misalignment but other things such as refraction and mount/OTA flexure
                        will (not "can" - *WILL*) cause drift in both axis. As I said, PEMPro
                        is very sensitive to centroid movement on the CCD. By the time you
                        noticed drift after 25 minutes that could easily have been many
                        arc-seconds. With RA swinging back and forth I wonder how you could
                        really be sure of how much dec drift occurred?

                        So, as I previously said try this experiment: take a long exposure to
                        see what kind of trails you see, or just two exposures 25 minutes
                        apart. Then compare the centroids with your favorite CCD application
                        to measure the amount of drift that occurred. Just make sure you know
                        which axis of the CCD is declination.

                        -Ray Gralak
                        Author of PEMPro

                        > -----Original Message-----
                        > From: RCX400@yahoogroups.com [mailto:RCX400@yahoogroups.com]
                        > On Behalf Of Michael
                        > Sent: Friday, June 02, 2006 4:32 AM
                        > To: RCX400@yahoogroups.com
                        > Subject: [RCX400] Re: PE and PEMPro
                        >
                        > Hi Jason,
                        >
                        > Well, Like I said, I drift aligned the scope with the CCD and Maxim
                        > DL for nearly 25 minutes until I noticed drift. That was unguided.
                        Of
                        > course the RA was all over the place with PE turned off but the star

                        > doesn't drift within 5-10 minutes time.
                        > That's why I am asking why PEMPro shows drift?
                        > Could it be the tracking rate, same as Brooks problem?
                        >
                        > Thanks,
                        >
                        > Michael
                        >
                        > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@...> wrote:
                        > >
                        > >
                        > >
                        > > Here is a simple test. Instead of pempro, just take a series
                        > > of exposures in MaxIm and see if the star drifts in dec.
                        > >
                        > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@> wrote:
                        > > >
                        > > > To be honest, I have a little of what Brooks got... this new
                        > > > obsession with PEMPro to produce the best PE possible on my RCX.
                        > > > When I initially used the software, I was surprised at the
                        > > unusually
                        > > > low PE it had from the beginning. I think it was because of Dr.
                        > > Clays
                        > > > work on the scope, PE peak 2 peak was <21 sec.
                        > > > But I noticed too that the DEC drift was off.. Brook, I saw that

                        > > same
                        > > > refinement article on the RCX and saw that my DEC drift was
                        worse
                        > > > than what was in that article and he called HIS substantial!
                        > > That's
                        > > > where I got hooked on the PEMPro data.
                        > > > I began a 3 day campaign on achieving the best polar alignment
                        > > > possible with what I had. I figured if the PE was that low,
                        > > imagine
                        > > > when the alignment was right on!
                        > > > Well, I drifted it with a 4mm reticle (9mm w/ barlow) until I
                        > > noticed
                        > > > no drift for 15-20 minutes.
                        > > > Then I drifted with the ST2k at F8 until again, no drift for 15-
                        > 20
                        > > > minutes, actually, while doing the east/west, I didn't get any
                        > > drift
                        > > > until after 25 minutes.
                        > > > I began acquiring data on PEMPro in the same area of sky I began

                        > > e/w
                        > > > drifting so flexure of any component would have been the same.
                        > > > The first 5 minutes of PEMPro data shows 10 seconds of +DEC
                        > drift.
                        > > >
                        > > >
                        > > > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@> wrote:
                        > > > >
                        > > > >
                        > > > > Was the CCD attached when you were doing the dec drift? Were
                        > > > > you doing the manual drift in the same part of the sky as
                        > > > > the PEMpro run?
                        > > > >
                        > > > > Changing the instrument package or slewing to a different
                        > > > > part of the sky is enough to change the alignment slightly
                        > > > > due to mount flexure.
                        > > > >
                        > > > >
                        > > > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@> wrote:
                        > > > > >
                        > > > > > Hi Brook and Jason,
                        > > > > > If I can just chime in here for a second regarding the
                        PEMPro
                        > > > drift
                        > > > > > as well?
                        > > > > > I was concerned while doing an aquision because I noticed a
                        > > very
                        > > > > high
                        > > > > > degree of drift on my DEC axis as well... I couldn't figure
                        > it
                        > > > out.
                        > > > > > My manual drift alignment procedures kept a star centered on

                        > > the
                        > > > > DEC
                        > > > > > axis for 15-20 minutes before it moves a few arc seconds but

                        > > the
                        > > > > > first 5 minutes of PEMPro data aquisition showed me almost
                        10
                        > > arc
                        > > > > > seconds of DEC (Y axis) drift.
                        > > > > > Why am I seeing this kind of drift when my scopes alignment
                        > > > appears
                        > > > > > to be so precise?
                        > > > > > Is this tracking modification Brook spoke of something I
                        > > should
                        > > > > > consider changing as well?
                        > > > > >
                        > > > > > Best Regards,
                        > > > > >
                        > > > > > Michael
                        > > > > >
                        > > > > >
                        > > > > > --- In RCX400@yahoogroups.com, "Brook Risner" <jegerbekk@>
                        > > wrote:
                        > > > > > >
                        > > > > > > Thanks Jason.
                        > > > > > >
                        > > > > > > I think I did settle on 5th Order as well. I'll try the
                        > tip
                        > > on
                        > > > > > using all
                        > > > > > > fundamentals, do you just use whole numbers, or do you go
                        > > for
                        > > > > some
                        > > > > > fractions
                        > > > > > > too?
                        > > > > > >
                        > > > > > > Changing the tracking rate was kind of a last resort.
                        > After
                        > > I
                        > > > > had
                        > > > > > gone
                        > > > > > > through the refine process and loaded the new curve to the

                        > > > scope
                        > > > > I
                        > > > > > still had
                        > > > > > > "drift". I first set it to custom rate to -5 and that
                        was
                        > > too
                        > > > > > much as I
                        > > > > > > saw right away that the drift went in the other direction.

                        > > I
                        > > > > > changed it to
                        > > > > > > -2 and voila, practically linear. I'll have to experiment

                        > > with
                        > > > > > this some
                        > > > > > > more...
                        > > > > > >
                        > > > > > > BTW, what kind of PE are you able to obtain?
                        > > > > > >
                        > > > > > > Somehow I'm finding this fun...
                        > > > > > >
                        > > > > > > - Brook
                        > > > > > >
                        > > > > > >
                        > > > > > > On 5/31/06, galaxy_jason <jasone@> wrote:
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > > you should not have to do any adjustments to the
                        tracking
                        > > > rate.
                        > > > > > > > This may be caused by refraction. The software
                        > compensates
                        > > for
                        > > > > > > > drift and assures that the correct number of counts are
                        > > put
                        > > > into
                        > > > > > > > the table.
                        > > > > > > >
                        > > > > > > > I have had very good luck with changing the drift
                        fitting
                        > > to
                        > > > > > > > a something other than linear, like 5th order. Also turn

                        > on
                        > > > > > > > ALL fundementals 1-40 or so. This takes a LONG time to
                        > > build
                        > > > > > > > a PE curve but it will follow the wiggles of the high
                        > order
                        > > > > > > > gears. Overall magnitude of the PE is less of a concern
                        > > than
                        > > > > > > > the sort arc-second/second errors.
                        > > > > > > >
                        > > > > > > > -Jason Ware
                        > > > > > > > http://www.galaxyphoto.com
                        > > > > > > >
                        > > > > > > > --- In RCX400@yahoogroups.com, "Brook Risner"
                        > <jegerbekk@>
                        > > > > wrote:
                        > > > > > > > >
                        > > > > > > > > I think I'm getting the hang of PEMpro and training
                        the
                        > > RCX
                        > > > > > mount.
                        > > > > > > > It looks
                        > > > > > > > > like I am approaching the advertised PE rate of less
                        > > than 5
                        > > > > > > > arcsec. PE
                        > > > > > > > > without PEC was initially >32 arcsec peak to peak.
                        > > After
                        > > > > > building
                        > > > > > > > a curve
                        > > > > > > > > and loading to the mount I got that down to to about 7

                        > > > arcsec.
                        > > > > > > > Built
                        > > > > > > > > another curve and refined the first and now it looks
                        > > like
                        > > > > about
                        > > > > > 5
                        > > > > > > > arcsec
                        > > > > > > > > peak to peak. (My last session didn't get all the way

                        > > > > through a
                        > > > > > > > full cycle
                        > > > > > > > > before trees block the view of my tracking stars, so I

                        > > > don't
                        > > > > > have
                        > > > > > > > full data
                        > > > > > > > > yet) I think I can refine it further and improve the
                        > PE
                        > > > even
                        > > > > > > > more. PEMPro
                        > > > > > > > > is the only way to go, in my humble opinion...
                        > > > > > > > >
                        > > > > > > > > I ended up changing the default tracking rate from
                        > > Sidereal
                        > > > to
                        > > > > > > > Custom -2,
                        > > > > > > > > because PEMPro was showing Y drift in RA, but Dec
                        > didn't
                        > > > look
                        > > > > > like
                        > > > > > > > it was
                        > > > > > > > > drifting. I'm not sure why the tracking rate would be

                        > > off
                        > > > > just
                        > > > > > a
                        > > > > > > > bit, but
                        > > > > > > > > after I adjusted it, the curve was fairly linear.
                        > > > > > > > >
                        > > > > > > > > I've included a link to some screen shots for
                        reference.
                        > > > > > > > >
                        > > > > > > > > http://home.earthlink.net/~jegerbekk/PE%20Results.JPG
                        > > > > > > > >
                        > > > > > > > > I would appreciate any comments or to hear of results
                        > > > others
                        > > > > are
                        > > > > > > > getting.
                        > > > > > > > >
                        > > > > > > > > Thanks,
                        > > > > > > > > Brook
                        > > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > > Yahoo! Groups Links
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > > >
                        > > > > > >
                        > > > > >
                        > > > >
                        > > >
                        > >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
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                      • Michael
                        Hi Ray, Yeah, thats a good point... why would tracking rates have to do anything with the Y Axis drift (dec). I must say, this can be awfully frustrating. I
                        Message 11 of 17 , Jun 2, 2006
                        • 0 Attachment
                          Hi Ray,
                          Yeah, thats a good point... why would tracking rates have to do
                          anything with the Y Axis drift (dec).
                          I must say, this can be awfully frustrating. I really thought I was
                          at the most optimal alignment I could achive with this system.
                          I still do not understand one thing. Granted, PEMPro is a sensitive
                          application for measuring movement, but all it's really doing is what
                          I did manually, that is, track a star using a CCD camera to measure
                          drift. So if I manually watch a star stationary in the DEC axis on my
                          screen for lets say, 10 minutes, why is PEMPro seeing drift of 10+
                          seconds in 5 minutes using the same techniques I am??
                          I will try the star trails test, I assume I should do this with RA
                          PEC turned on, right? Otherwise I will record the PE on the images as
                          well.

                          Thank you,

                          Michael

                          --- In RCX400@yahoogroups.com, "Ray Gralak" <rgr@...> wrote:
                          >
                          > Hi Michael,
                          >
                          > Dec never moves so it cannot be tracking! It is probably polar
                          > misalignment but other things such as refraction and mount/OTA
                          flexure
                          > will (not "can" - *WILL*) cause drift in both axis. As I said,
                          PEMPro
                          > is very sensitive to centroid movement on the CCD. By the time you
                          > noticed drift after 25 minutes that could easily have been many
                          > arc-seconds. With RA swinging back and forth I wonder how you could
                          > really be sure of how much dec drift occurred?
                          >
                          > So, as I previously said try this experiment: take a long exposure
                          to
                          > see what kind of trails you see, or just two exposures 25 minutes
                          > apart. Then compare the centroids with your favorite CCD application
                          > to measure the amount of drift that occurred. Just make sure you
                          know
                          > which axis of the CCD is declination.
                          >
                          > -Ray Gralak
                          > Author of PEMPro
                          >
                          > > -----Original Message-----
                          > > From: RCX400@yahoogroups.com [mailto:RCX400@yahoogroups.com]
                          > > On Behalf Of Michael
                          > > Sent: Friday, June 02, 2006 4:32 AM
                          > > To: RCX400@yahoogroups.com
                          > > Subject: [RCX400] Re: PE and PEMPro
                          > >
                          > > Hi Jason,
                          > >
                          > > Well, Like I said, I drift aligned the scope with the CCD and
                          Maxim
                          > > DL for nearly 25 minutes until I noticed drift. That was unguided.
                          > Of
                          > > course the RA was all over the place with PE turned off but the
                          star
                          >
                          > > doesn't drift within 5-10 minutes time.
                          > > That's why I am asking why PEMPro shows drift?
                          > > Could it be the tracking rate, same as Brooks problem?
                          > >
                          > > Thanks,
                          > >
                          > > Michael
                          > >
                          > > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@> wrote:
                          > > >
                          > > >
                          > > >
                          > > > Here is a simple test. Instead of pempro, just take a series
                          > > > of exposures in MaxIm and see if the star drifts in dec.
                          > > >
                          > > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@> wrote:
                          > > > >
                          > > > > To be honest, I have a little of what Brooks got... this new
                          > > > > obsession with PEMPro to produce the best PE possible on my
                          RCX.
                          > > > > When I initially used the software, I was surprised at the
                          > > > unusually
                          > > > > low PE it had from the beginning. I think it was because of
                          Dr.
                          > > > Clays
                          > > > > work on the scope, PE peak 2 peak was <21 sec.
                          > > > > But I noticed too that the DEC drift was off.. Brook, I saw
                          that
                          >
                          > > > same
                          > > > > refinement article on the RCX and saw that my DEC drift was
                          > worse
                          > > > > than what was in that article and he called HIS substantial!
                          > > > That's
                          > > > > where I got hooked on the PEMPro data.
                          > > > > I began a 3 day campaign on achieving the best polar
                          alignment
                          > > > > possible with what I had. I figured if the PE was that low,
                          > > > imagine
                          > > > > when the alignment was right on!
                          > > > > Well, I drifted it with a 4mm reticle (9mm w/ barlow) until I
                          > > > noticed
                          > > > > no drift for 15-20 minutes.
                          > > > > Then I drifted with the ST2k at F8 until again, no drift for
                          15-
                          > > 20
                          > > > > minutes, actually, while doing the east/west, I didn't get
                          any
                          > > > drift
                          > > > > until after 25 minutes.
                          > > > > I began acquiring data on PEMPro in the same area of sky I
                          began
                          >
                          > > > e/w
                          > > > > drifting so flexure of any component would have been the
                          same.
                          > > > > The first 5 minutes of PEMPro data shows 10 seconds of +DEC
                          > > drift.
                          > > > >
                          > > > >
                          > > > > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@> wrote:
                          > > > > >
                          > > > > >
                          > > > > > Was the CCD attached when you were doing the dec drift? Were
                          > > > > > you doing the manual drift in the same part of the sky as
                          > > > > > the PEMpro run?
                          > > > > >
                          > > > > > Changing the instrument package or slewing to a different
                          > > > > > part of the sky is enough to change the alignment slightly
                          > > > > > due to mount flexure.
                          > > > > >
                          > > > > >
                          > > > > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@>
                          wrote:
                          > > > > > >
                          > > > > > > Hi Brook and Jason,
                          > > > > > > If I can just chime in here for a second regarding the
                          > PEMPro
                          > > > > drift
                          > > > > > > as well?
                          > > > > > > I was concerned while doing an aquision because I noticed
                          a
                          > > > very
                          > > > > > high
                          > > > > > > degree of drift on my DEC axis as well... I couldn't
                          figure
                          > > it
                          > > > > out.
                          > > > > > > My manual drift alignment procedures kept a star centered
                          on
                          >
                          > > > the
                          > > > > > DEC
                          > > > > > > axis for 15-20 minutes before it moves a few arc seconds
                          but
                          >
                          > > > the
                          > > > > > > first 5 minutes of PEMPro data aquisition showed me almost
                          > 10
                          > > > arc
                          > > > > > > seconds of DEC (Y axis) drift.
                          > > > > > > Why am I seeing this kind of drift when my scopes
                          alignment
                          > > > > appears
                          > > > > > > to be so precise?
                          > > > > > > Is this tracking modification Brook spoke of something I
                          > > > should
                          > > > > > > consider changing as well?
                          > > > > > >
                          > > > > > > Best Regards,
                          > > > > > >
                          > > > > > > Michael
                          > > > > > >
                          > > > > > >
                          > > > > > > --- In RCX400@yahoogroups.com, "Brook Risner"
                          <jegerbekk@>
                          > > > wrote:
                          > > > > > > >
                          > > > > > > > Thanks Jason.
                          > > > > > > >
                          > > > > > > > I think I did settle on 5th Order as well. I'll try
                          the
                          > > tip
                          > > > on
                          > > > > > > using all
                          > > > > > > > fundamentals, do you just use whole numbers, or do you
                          go
                          > > > for
                          > > > > > some
                          > > > > > > fractions
                          > > > > > > > too?
                          > > > > > > >
                          > > > > > > > Changing the tracking rate was kind of a last resort.
                          > > After
                          > > > I
                          > > > > > had
                          > > > > > > gone
                          > > > > > > > through the refine process and loaded the new curve to
                          the
                          >
                          > > > > scope
                          > > > > > I
                          > > > > > > still had
                          > > > > > > > "drift". I first set it to custom rate to -5 and that
                          > was
                          > > > too
                          > > > > > > much as I
                          > > > > > > > saw right away that the drift went in the other
                          direction.
                          >
                          > > > I
                          > > > > > > changed it to
                          > > > > > > > -2 and voila, practically linear. I'll have to
                          experiment
                          >
                          > > > with
                          > > > > > > this some
                          > > > > > > > more...
                          > > > > > > >
                          > > > > > > > BTW, what kind of PE are you able to obtain?
                          > > > > > > >
                          > > > > > > > Somehow I'm finding this fun...
                          > > > > > > >
                          > > > > > > > - Brook
                          > > > > > > >
                          > > > > > > >
                          > > > > > > > On 5/31/06, galaxy_jason <jasone@> wrote:
                          > > > > > > > >
                          > > > > > > > >
                          > > > > > > > >
                          > > > > > > > > you should not have to do any adjustments to the
                          > tracking
                          > > > > rate.
                          > > > > > > > > This may be caused by refraction. The software
                          > > compensates
                          > > > for
                          > > > > > > > > drift and assures that the correct number of counts
                          are
                          > > > put
                          > > > > into
                          > > > > > > > > the table.
                          > > > > > > > >
                          > > > > > > > > I have had very good luck with changing the drift
                          > fitting
                          > > > to
                          > > > > > > > > a something other than linear, like 5th order. Also
                          turn
                          >
                          > > on
                          > > > > > > > > ALL fundementals 1-40 or so. This takes a LONG time
                          to
                          > > > build
                          > > > > > > > > a PE curve but it will follow the wiggles of the high
                          > > order
                          > > > > > > > > gears. Overall magnitude of the PE is less of a
                          concern
                          > > > than
                          > > > > > > > > the sort arc-second/second errors.
                          > > > > > > > >
                          > > > > > > > > -Jason Ware
                          > > > > > > > > http://www.galaxyphoto.com
                          > > > > > > > >
                          > > > > > > > > --- In RCX400@yahoogroups.com, "Brook Risner"
                          > > <jegerbekk@>
                          > > > > > wrote:
                          > > > > > > > > >
                          > > > > > > > > > I think I'm getting the hang of PEMpro and training
                          > the
                          > > > RCX
                          > > > > > > mount.
                          > > > > > > > > It looks
                          > > > > > > > > > like I am approaching the advertised PE rate of
                          less
                          > > > than 5
                          > > > > > > > > arcsec. PE
                          > > > > > > > > > without PEC was initially >32 arcsec peak to peak.
                          > > > After
                          > > > > > > building
                          > > > > > > > > a curve
                          > > > > > > > > > and loading to the mount I got that down to to
                          about 7
                          >
                          > > > > arcsec.
                          > > > > > > > > Built
                          > > > > > > > > > another curve and refined the first and now it
                          looks
                          > > > like
                          > > > > > about
                          > > > > > > 5
                          > > > > > > > > arcsec
                          > > > > > > > > > peak to peak. (My last session didn't get all the
                          way
                          >
                          > > > > > through a
                          > > > > > > > > full cycle
                          > > > > > > > > > before trees block the view of my tracking stars,
                          so I
                          >
                          > > > > don't
                          > > > > > > have
                          > > > > > > > > full data
                          > > > > > > > > > yet) I think I can refine it further and improve
                          the
                          > > PE
                          > > > > even
                          > > > > > > > > more. PEMPro
                          > > > > > > > > > is the only way to go, in my humble opinion...
                          > > > > > > > > >
                          > > > > > > > > > I ended up changing the default tracking rate from
                          > > > Sidereal
                          > > > > to
                          > > > > > > > > Custom -2,
                          > > > > > > > > > because PEMPro was showing Y drift in RA, but Dec
                          > > didn't
                          > > > > look
                          > > > > > > like
                          > > > > > > > > it was
                          > > > > > > > > > drifting. I'm not sure why the tracking rate would
                          be
                          >
                          > > > off
                          > > > > > just
                          > > > > > > a
                          > > > > > > > > bit, but
                          > > > > > > > > > after I adjusted it, the curve was fairly linear.
                          > > > > > > > > >
                          > > > > > > > > > I've included a link to some screen shots for
                          > reference.
                          > > > > > > > > >
                          > > > > > > > > > http://home.earthlink.net/~jegerbekk/PE%
                          20Results.JPG
                          > > > > > > > > >
                          > > > > > > > > > I would appreciate any comments or to hear of
                          results
                          > > > > others
                          > > > > > are
                          > > > > > > > > getting.
                          > > > > > > > > >
                          > > > > > > > > > Thanks,
                          > > > > > > > > > Brook
                          > > > > > > > > >
                          > > > > > > > >
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                        • Ray Gralak
                          Hi Michael, Even with perfect tracking and no telescope flexure, there will be apparent drift from refraction. The effects of refraction will be in both axes
                          Message 12 of 17 , Jun 2, 2006
                          • 0 Attachment
                            Hi Michael,

                            Even with perfect tracking and no telescope flexure, there will be
                            apparent drift from refraction. The effects of refraction will be in
                            both axes (RA and Dec). However, I probably could compensate for
                            refraction effects in PEMPro so I will put that into my to-do list.

                            -Ray

                            > -----Original Message-----
                            > From: RCX400@yahoogroups.com [mailto:RCX400@yahoogroups.com]
                            > On Behalf Of Michael
                            > Sent: Friday, June 02, 2006 8:56 AM
                            > To: RCX400@yahoogroups.com
                            > Subject: [RCX400] Re: PE and PEMPro
                            >
                            > Hi Ray,
                            > Yeah, thats a good point... why would tracking rates have to do
                            > anything with the Y Axis drift (dec).
                            > I must say, this can be awfully frustrating. I really thought I was
                            > at the most optimal alignment I could achive with this system.
                            > I still do not understand one thing. Granted, PEMPro is a sensitive
                            > application for measuring movement, but all it's really doing is
                            what
                            > I did manually, that is, track a star using a CCD camera to measure
                            > drift. So if I manually watch a star stationary in the DEC axis on
                            my
                            > screen for lets say, 10 minutes, why is PEMPro seeing drift of 10+
                            > seconds in 5 minutes using the same techniques I am??
                            > I will try the star trails test, I assume I should do this with RA
                            > PEC turned on, right? Otherwise I will record the PE on the images
                            as
                            > well.
                            >
                            > Thank you,
                            >
                            > Michael
                            >
                            > --- In RCX400@yahoogroups.com, "Ray Gralak" <rgr@...> wrote:
                            > >
                            > > Hi Michael,
                            > >
                            > > Dec never moves so it cannot be tracking! It is probably polar
                            > > misalignment but other things such as refraction and mount/OTA
                            > flexure
                            > > will (not "can" - *WILL*) cause drift in both axis. As I said,
                            > PEMPro
                            > > is very sensitive to centroid movement on the CCD. By the time you
                            > > noticed drift after 25 minutes that could easily have been many
                            > > arc-seconds. With RA swinging back and forth I wonder how you
                            could
                            > > really be sure of how much dec drift occurred?
                            > >
                            > > So, as I previously said try this experiment: take a long exposure

                            > to
                            > > see what kind of trails you see, or just two exposures 25 minutes
                            > > apart. Then compare the centroids with your favorite CCD
                            application
                            > > to measure the amount of drift that occurred. Just make sure you
                            > know
                            > > which axis of the CCD is declination.
                            > >
                            > > -Ray Gralak
                            > > Author of PEMPro
                            > >
                            > > > -----Original Message-----
                            > > > From: RCX400@yahoogroups.com [mailto:RCX400@yahoogroups.com]
                            > > > On Behalf Of Michael
                            > > > Sent: Friday, June 02, 2006 4:32 AM
                            > > > To: RCX400@yahoogroups.com
                            > > > Subject: [RCX400] Re: PE and PEMPro
                            > > >
                            > > > Hi Jason,
                            > > >
                            > > > Well, Like I said, I drift aligned the scope with the CCD and
                            > Maxim
                            > > > DL for nearly 25 minutes until I noticed drift. That was
                            unguided.
                            > > Of
                            > > > course the RA was all over the place with PE turned off but the
                            > star
                            > >
                            > > > doesn't drift within 5-10 minutes time.
                            > > > That's why I am asking why PEMPro shows drift?
                            > > > Could it be the tracking rate, same as Brooks problem?
                            > > >
                            > > > Thanks,
                            > > >
                            > > > Michael
                            > > >
                            > > > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@> wrote:
                            > > > >
                            > > > >
                            > > > >
                            > > > > Here is a simple test. Instead of pempro, just take a series
                            > > > > of exposures in MaxIm and see if the star drifts in dec.
                            > > > >
                            > > > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@> wrote:
                            > > > > >
                            > > > > > To be honest, I have a little of what Brooks got... this new

                            > > > > > obsession with PEMPro to produce the best PE possible on my
                            > RCX.
                            > > > > > When I initially used the software, I was surprised at the
                            > > > > unusually
                            > > > > > low PE it had from the beginning. I think it was because of
                            > Dr.
                            > > > > Clays
                            > > > > > work on the scope, PE peak 2 peak was <21 sec.
                            > > > > > But I noticed too that the DEC drift was off.. Brook, I saw
                            > that
                            > >
                            > > > > same
                            > > > > > refinement article on the RCX and saw that my DEC drift was
                            > > worse
                            > > > > > than what was in that article and he called HIS substantial!

                            > > > > That's
                            > > > > > where I got hooked on the PEMPro data.
                            > > > > > I began a 3 day campaign on achieving the best polar
                            > alignment
                            > > > > > possible with what I had. I figured if the PE was that low,
                            > > > > imagine
                            > > > > > when the alignment was right on!
                            > > > > > Well, I drifted it with a 4mm reticle (9mm w/ barlow) until
                            I
                            > > > > noticed
                            > > > > > no drift for 15-20 minutes.
                            > > > > > Then I drifted with the ST2k at F8 until again, no drift for

                            > 15-
                            > > > 20
                            > > > > > minutes, actually, while doing the east/west, I didn't get
                            > any
                            > > > > drift
                            > > > > > until after 25 minutes.
                            > > > > > I began acquiring data on PEMPro in the same area of sky I
                            > began
                            > >
                            > > > > e/w
                            > > > > > drifting so flexure of any component would have been the
                            > same.
                            > > > > > The first 5 minutes of PEMPro data shows 10 seconds of +DEC
                            > > > drift.
                            > > > > >
                            > > > > >
                            > > > > > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@>
                            wrote:
                            > > > > > >
                            > > > > > >
                            > > > > > > Was the CCD attached when you were doing the dec drift?
                            Were
                            > > > > > > you doing the manual drift in the same part of the sky as
                            > > > > > > the PEMpro run?
                            > > > > > >
                            > > > > > > Changing the instrument package or slewing to a different
                            > > > > > > part of the sky is enough to change the alignment slightly
                            > > > > > > due to mount flexure.
                            > > > > > >
                            > > > > > >
                            > > > > > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@>
                            > wrote:
                            > > > > > > >
                            > > > > > > > Hi Brook and Jason,
                            > > > > > > > If I can just chime in here for a second regarding the
                            > > PEMPro
                            > > > > > drift
                            > > > > > > > as well?
                            > > > > > > > I was concerned while doing an aquision because I
                            noticed
                            > a
                            > > > > very
                            > > > > > > high
                            > > > > > > > degree of drift on my DEC axis as well... I couldn't
                            > figure
                            > > > it
                            > > > > > out.
                            > > > > > > > My manual drift alignment procedures kept a star
                            centered
                            > on
                            > >
                            > > > > the
                            > > > > > > DEC
                            > > > > > > > axis for 15-20 minutes before it moves a few arc seconds

                            > but
                            > >
                            > > > > the
                            > > > > > > > first 5 minutes of PEMPro data aquisition showed me
                            almost
                            > > 10
                            > > > > arc
                            > > > > > > > seconds of DEC (Y axis) drift.
                            > > > > > > > Why am I seeing this kind of drift when my scopes
                            > alignment
                            > > > > > appears
                            > > > > > > > to be so precise?
                            > > > > > > > Is this tracking modification Brook spoke of something I

                            > > > > should
                            > > > > > > > consider changing as well?
                            > > > > > > >
                            > > > > > > > Best Regards,
                            > > > > > > >
                            > > > > > > > Michael
                            > > > > > > >
                            > > > > > > >
                            > > > > > > > --- In RCX400@yahoogroups.com, "Brook Risner"
                            > <jegerbekk@>
                            > > > > wrote:
                            > > > > > > > >
                            > > > > > > > > Thanks Jason.
                            > > > > > > > >
                            > > > > > > > > I think I did settle on 5th Order as well. I'll try
                            > the
                            > > > tip
                            > > > > on
                            > > > > > > > using all
                            > > > > > > > > fundamentals, do you just use whole numbers, or do you

                            > go
                            > > > > for
                            > > > > > > some
                            > > > > > > > fractions
                            > > > > > > > > too?
                            > > > > > > > >
                            > > > > > > > > Changing the tracking rate was kind of a last resort.

                            > > > After
                            > > > > I
                            > > > > > > had
                            > > > > > > > gone
                            > > > > > > > > through the refine process and loaded the new curve to

                            > the
                            > >
                            > > > > > scope
                            > > > > > > I
                            > > > > > > > still had
                            > > > > > > > > "drift". I first set it to custom rate to -5 and
                            that
                            > > was
                            > > > > too
                            > > > > > > > much as I
                            > > > > > > > > saw right away that the drift went in the other
                            > direction.
                            > >
                            > > > > I
                            > > > > > > > changed it to
                            > > > > > > > > -2 and voila, practically linear. I'll have to
                            > experiment
                            > >
                            > > > > with
                            > > > > > > > this some
                            > > > > > > > > more...
                            > > > > > > > >
                            > > > > > > > > BTW, what kind of PE are you able to obtain?
                            > > > > > > > >
                            > > > > > > > > Somehow I'm finding this fun...
                            > > > > > > > >
                            > > > > > > > > - Brook
                            > > > > > > > >
                            > > > > > > > >
                            > > > > > > > > On 5/31/06, galaxy_jason <jasone@> wrote:
                            > > > > > > > > >
                            > > > > > > > > >
                            > > > > > > > > >
                            > > > > > > > > > you should not have to do any adjustments to the
                            > > tracking
                            > > > > > rate.
                            > > > > > > > > > This may be caused by refraction. The software
                            > > > compensates
                            > > > > for
                            > > > > > > > > > drift and assures that the correct number of counts
                            > are
                            > > > > put
                            > > > > > into
                            > > > > > > > > > the table.
                            > > > > > > > > >
                            > > > > > > > > > I have had very good luck with changing the drift
                            > > fitting
                            > > > > to
                            > > > > > > > > > a something other than linear, like 5th order. Also
                            > turn
                            > >
                            > > > on
                            > > > > > > > > > ALL fundementals 1-40 or so. This takes a LONG time
                            > to
                            > > > > build
                            > > > > > > > > > a PE curve but it will follow the wiggles of the
                            high
                            > > > order
                            > > > > > > > > > gears. Overall magnitude of the PE is less of a
                            > concern
                            > > > > than
                            > > > > > > > > > the sort arc-second/second errors.
                            > > > > > > > > >
                            > > > > > > > > > -Jason Ware
                            > > > > > > > > > http://www.galaxyphoto.com
                            > > > > > > > > >
                            > > > > > > > > > --- In RCX400@yahoogroups.com, "Brook Risner"
                            > > > <jegerbekk@>
                            > > > > > > wrote:
                            > > > > > > > > > >
                            > > > > > > > > > > I think I'm getting the hang of PEMpro and
                            training
                            > > the
                            > > > > RCX
                            > > > > > > > mount.
                            > > > > > > > > > It looks
                            > > > > > > > > > > like I am approaching the advertised PE rate of
                            > less
                            > > > > than 5
                            > > > > > > > > > arcsec. PE
                            > > > > > > > > > > without PEC was initially >32 arcsec peak to peak.

                            > > > > After
                            > > > > > > > building
                            > > > > > > > > > a curve
                            > > > > > > > > > > and loading to the mount I got that down to to
                            > about 7
                            > >
                            > > > > > arcsec.
                            > > > > > > > > > Built
                            > > > > > > > > > > another curve and refined the first and now it
                            > looks
                            > > > > like
                            > > > > > > about
                            > > > > > > > 5
                            > > > > > > > > > arcsec
                            > > > > > > > > > > peak to peak. (My last session didn't get all the

                            > way
                            > >
                            > > > > > > through a
                            > > > > > > > > > full cycle
                            > > > > > > > > > > before trees block the view of my tracking stars,
                            > so I
                            > >
                            > > > > > don't
                            > > > > > > > have
                            > > > > > > > > > full data
                            > > > > > > > > > > yet) I think I can refine it further and improve
                            > the
                            > > > PE
                            > > > > > even
                            > > > > > > > > > more. PEMPro
                            > > > > > > > > > > is the only way to go, in my humble opinion...
                            > > > > > > > > > >
                            > > > > > > > > > > I ended up changing the default tracking rate from

                            > > > > Sidereal
                            > > > > > to
                            > > > > > > > > > Custom -2,
                            > > > > > > > > > > because PEMPro was showing Y drift in RA, but Dec
                            > > > didn't
                            > > > > > look
                            > > > > > > > like
                            > > > > > > > > > it was
                            > > > > > > > > > > drifting. I'm not sure why the tracking rate
                            would
                            > be
                            > >
                            > > > > off
                            > > > > > > just
                            > > > > > > > a
                            > > > > > > > > > bit, but
                            > > > > > > > > > > after I adjusted it, the curve was fairly linear.
                            > > > > > > > > > >
                            > > > > > > > > > > I've included a link to some screen shots for
                            > > reference.
                            > > > > > > > > > >
                            > > > > > > > > > > http://home.earthlink.net/~jegerbekk/PE%
                            > 20Results.JPG
                            > > > > > > > > > >
                            > > > > > > > > > > I would appreciate any comments or to hear of
                            > results
                            > > > > > others
                            > > > > > > are
                            > > > > > > > > > getting.
                            > > > > > > > > > >
                            > > > > > > > > > > Thanks,
                            > > > > > > > > > > Brook
                            > > > > > > > > > >
                            > > > > > > > > >
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                            > > > > > > > > >
                            > > > > > > > > >
                            > > > > > > > > >
                            > > > > > > > > > Yahoo! Groups Links
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                            > > iscount+telescope&w6=Astronomy+telescope&c=6&s=130>
                            > > &.sig=oJI1EMyhfxHvF_MmrTjwnA> Buy telescope
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                            > > e&w2=Buy+telescope&w3=Meade+telescopes&w4=Telescope+eyepieces&w5>
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                            > > > SamtIlMenLXWZlG4MQ> Meade telescopes
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                            > > ope&c=6&s=130&.sig=O4knfrz5RLaQkYzf5Hntfw>
                            > > > Telescope eyepieces
                            > > > <http://groups.yahoo.com/gads?t=ms&k=Telescope+eyepieces&w1=Te
                            > > lescope&w2=Buy+telescope&w3=Meade+telescopes&w4>
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                          • Michael
                            Hi Ray, So let me put this into a perspective I can understand. No matter how good I get my alignment, I will never eliminate the drift while aquiring data
                            Message 13 of 17 , Jun 3, 2006
                            • 0 Attachment
                              Hi Ray,
                              So let me put this into a perspective I can understand.
                              No matter how good I get my alignment, I will never eliminate the
                              drift while aquiring data with PEMPro, is that a correct statement?
                              If thats the fact, then thats something I can live with. I just don't
                              want to be chasing a ghost here. I am very impressed with PEMPro's
                              capabilities. My PE WITHOUT a refinement curve went from 21 seconds
                              to +8.8/-9.4 with an RMS of 1.962 while set to Linear Drift fitting.
                              It's even lower, though not substantially using a 5th order fit.
                              Because the drift readings for this run were X Drift -0.019887 and Y
                              Drift 0.013626, I never did aquire refinement data because I was
                              under the impression that these drifts were too great and I've been
                              occupied with trying to eliminate or at least decrease them before
                              aquiring more data. If you're telling me that I'm stuck with it no
                              matter how precise my alignment, I'll just pick up where I left off.
                              Thoughts?

                              Michael

                              --- In RCX400@yahoogroups.com, "Ray Gralak" <rgr@...> wrote:
                              >
                              > Hi Michael,
                              >
                              > Even with perfect tracking and no telescope flexure, there will be
                              > apparent drift from refraction. The effects of refraction will be in
                              > both axes (RA and Dec). However, I probably could compensate for
                              > refraction effects in PEMPro so I will put that into my to-do list.
                              >
                              > -Ray
                              >
                              > > -----Original Message-----
                              > > From: RCX400@yahoogroups.com [mailto:RCX400@yahoogroups.com]
                              > > On Behalf Of Michael
                              > > Sent: Friday, June 02, 2006 8:56 AM
                              > > To: RCX400@yahoogroups.com
                              > > Subject: [RCX400] Re: PE and PEMPro
                              > >
                              > > Hi Ray,
                              > > Yeah, thats a good point... why would tracking rates have to do
                              > > anything with the Y Axis drift (dec).
                              > > I must say, this can be awfully frustrating. I really thought I
                              was
                              > > at the most optimal alignment I could achive with this system.
                              > > I still do not understand one thing. Granted, PEMPro is a
                              sensitive
                              > > application for measuring movement, but all it's really doing is
                              > what
                              > > I did manually, that is, track a star using a CCD camera to
                              measure
                              > > drift. So if I manually watch a star stationary in the DEC axis on
                              > my
                              > > screen for lets say, 10 minutes, why is PEMPro seeing drift of
                              10+
                              > > seconds in 5 minutes using the same techniques I am??
                              > > I will try the star trails test, I assume I should do this with
                              RA
                              > > PEC turned on, right? Otherwise I will record the PE on the images
                              > as
                              > > well.
                              > >
                              > > Thank you,
                              > >
                              > > Michael
                              > >
                              > > --- In RCX400@yahoogroups.com, "Ray Gralak" <rgr@> wrote:
                              > > >
                              > > > Hi Michael,
                              > > >
                              > > > Dec never moves so it cannot be tracking! It is probably polar
                              > > > misalignment but other things such as refraction and mount/OTA
                              > > flexure
                              > > > will (not "can" - *WILL*) cause drift in both axis. As I said,
                              > > PEMPro
                              > > > is very sensitive to centroid movement on the CCD. By the time
                              you
                              > > > noticed drift after 25 minutes that could easily have been many
                              > > > arc-seconds. With RA swinging back and forth I wonder how you
                              > could
                              > > > really be sure of how much dec drift occurred?
                              > > >
                              > > > So, as I previously said try this experiment: take a long
                              exposure
                              >
                              > > to
                              > > > see what kind of trails you see, or just two exposures 25
                              minutes
                              > > > apart. Then compare the centroids with your favorite CCD
                              > application
                              > > > to measure the amount of drift that occurred. Just make sure
                              you
                              > > know
                              > > > which axis of the CCD is declination.
                              > > >
                              > > > -Ray Gralak
                              > > > Author of PEMPro
                              > > >
                              > > > > -----Original Message-----
                              > > > > From: RCX400@yahoogroups.com [mailto:RCX400@yahoogroups.com]
                              > > > > On Behalf Of Michael
                              > > > > Sent: Friday, June 02, 2006 4:32 AM
                              > > > > To: RCX400@yahoogroups.com
                              > > > > Subject: [RCX400] Re: PE and PEMPro
                              > > > >
                              > > > > Hi Jason,
                              > > > >
                              > > > > Well, Like I said, I drift aligned the scope with the CCD and
                              > > Maxim
                              > > > > DL for nearly 25 minutes until I noticed drift. That was
                              > unguided.
                              > > > Of
                              > > > > course the RA was all over the place with PE turned off but
                              the
                              > > star
                              > > >
                              > > > > doesn't drift within 5-10 minutes time.
                              > > > > That's why I am asking why PEMPro shows drift?
                              > > > > Could it be the tracking rate, same as Brooks problem?
                              > > > >
                              > > > > Thanks,
                              > > > >
                              > > > > Michael
                              > > > >
                              > > > > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@> wrote:
                              > > > > >
                              > > > > >
                              > > > > >
                              > > > > > Here is a simple test. Instead of pempro, just take a series
                              > > > > > of exposures in MaxIm and see if the star drifts in dec.
                              > > > > >
                              > > > > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@>
                              wrote:
                              > > > > > >
                              > > > > > > To be honest, I have a little of what Brooks got... this
                              new
                              >
                              > > > > > > obsession with PEMPro to produce the best PE possible on
                              my
                              > > RCX.
                              > > > > > > When I initially used the software, I was surprised at
                              the
                              > > > > > unusually
                              > > > > > > low PE it had from the beginning. I think it was because
                              of
                              > > Dr.
                              > > > > > Clays
                              > > > > > > work on the scope, PE peak 2 peak was <21 sec.
                              > > > > > > But I noticed too that the DEC drift was off.. Brook, I
                              saw
                              > > that
                              > > >
                              > > > > > same
                              > > > > > > refinement article on the RCX and saw that my DEC drift
                              was
                              > > > worse
                              > > > > > > than what was in that article and he called HIS
                              substantial!
                              >
                              > > > > > That's
                              > > > > > > where I got hooked on the PEMPro data.
                              > > > > > > I began a 3 day campaign on achieving the best polar
                              > > alignment
                              > > > > > > possible with what I had. I figured if the PE was that
                              low,
                              > > > > > imagine
                              > > > > > > when the alignment was right on!
                              > > > > > > Well, I drifted it with a 4mm reticle (9mm w/ barlow)
                              until
                              > I
                              > > > > > noticed
                              > > > > > > no drift for 15-20 minutes.
                              > > > > > > Then I drifted with the ST2k at F8 until again, no drift
                              for
                              >
                              > > 15-
                              > > > > 20
                              > > > > > > minutes, actually, while doing the east/west, I didn't
                              get
                              > > any
                              > > > > > drift
                              > > > > > > until after 25 minutes.
                              > > > > > > I began acquiring data on PEMPro in the same area of sky
                              I
                              > > began
                              > > >
                              > > > > > e/w
                              > > > > > > drifting so flexure of any component would have been the
                              > > same.
                              > > > > > > The first 5 minutes of PEMPro data shows 10 seconds of
                              +DEC
                              > > > > drift.
                              > > > > > >
                              > > > > > >
                              > > > > > > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@>
                              > wrote:
                              > > > > > > >
                              > > > > > > >
                              > > > > > > > Was the CCD attached when you were doing the dec drift?
                              > Were
                              > > > > > > > you doing the manual drift in the same part of the sky
                              as
                              > > > > > > > the PEMpro run?
                              > > > > > > >
                              > > > > > > > Changing the instrument package or slewing to a
                              different
                              > > > > > > > part of the sky is enough to change the alignment
                              slightly
                              > > > > > > > due to mount flexure.
                              > > > > > > >
                              > > > > > > >
                              > > > > > > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@>
                              > > wrote:
                              > > > > > > > >
                              > > > > > > > > Hi Brook and Jason,
                              > > > > > > > > If I can just chime in here for a second regarding the
                              > > > PEMPro
                              > > > > > > drift
                              > > > > > > > > as well?
                              > > > > > > > > I was concerned while doing an aquision because I
                              > noticed
                              > > a
                              > > > > > very
                              > > > > > > > high
                              > > > > > > > > degree of drift on my DEC axis as well... I couldn't
                              > > figure
                              > > > > it
                              > > > > > > out.
                              > > > > > > > > My manual drift alignment procedures kept a star
                              > centered
                              > > on
                              > > >
                              > > > > > the
                              > > > > > > > DEC
                              > > > > > > > > axis for 15-20 minutes before it moves a few arc
                              seconds
                              >
                              > > but
                              > > >
                              > > > > > the
                              > > > > > > > > first 5 minutes of PEMPro data aquisition showed me
                              > almost
                              > > > 10
                              > > > > > arc
                              > > > > > > > > seconds of DEC (Y axis) drift.
                              > > > > > > > > Why am I seeing this kind of drift when my scopes
                              > > alignment
                              > > > > > > appears
                              > > > > > > > > to be so precise?
                              > > > > > > > > Is this tracking modification Brook spoke of
                              something I
                              >
                              > > > > > should
                              > > > > > > > > consider changing as well?
                              > > > > > > > >
                              > > > > > > > > Best Regards,
                              > > > > > > > >
                              > > > > > > > > Michael
                              > > > > > > > >
                              > > > > > > > >
                              > > > > > > > > --- In RCX400@yahoogroups.com, "Brook Risner"
                              > > <jegerbekk@>
                              > > > > > wrote:
                              > > > > > > > > >
                              > > > > > > > > > Thanks Jason.
                              > > > > > > > > >
                              > > > > > > > > > I think I did settle on 5th Order as well. I'll
                              try
                              > > the
                              > > > > tip
                              > > > > > on
                              > > > > > > > > using all
                              > > > > > > > > > fundamentals, do you just use whole numbers, or do
                              you
                              >
                              > > go
                              > > > > > for
                              > > > > > > > some
                              > > > > > > > > fractions
                              > > > > > > > > > too?
                              > > > > > > > > >
                              > > > > > > > > > Changing the tracking rate was kind of a last
                              resort.
                              >
                              > > > > After
                              > > > > > I
                              > > > > > > > had
                              > > > > > > > > gone
                              > > > > > > > > > through the refine process and loaded the new curve
                              to
                              >
                              > > the
                              > > >
                              > > > > > > scope
                              > > > > > > > I
                              > > > > > > > > still had
                              > > > > > > > > > "drift". I first set it to custom rate to -5 and
                              > that
                              > > > was
                              > > > > > too
                              > > > > > > > > much as I
                              > > > > > > > > > saw right away that the drift went in the other
                              > > direction.
                              > > >
                              > > > > > I
                              > > > > > > > > changed it to
                              > > > > > > > > > -2 and voila, practically linear. I'll have to
                              > > experiment
                              > > >
                              > > > > > with
                              > > > > > > > > this some
                              > > > > > > > > > more...
                              > > > > > > > > >
                              > > > > > > > > > BTW, what kind of PE are you able to obtain?
                              > > > > > > > > >
                              > > > > > > > > > Somehow I'm finding this fun...
                              > > > > > > > > >
                              > > > > > > > > > - Brook
                              > > > > > > > > >
                              > > > > > > > > >
                              > > > > > > > > > On 5/31/06, galaxy_jason <jasone@> wrote:
                              > > > > > > > > > >
                              > > > > > > > > > >
                              > > > > > > > > > >
                              > > > > > > > > > > you should not have to do any adjustments to the
                              > > > tracking
                              > > > > > > rate.
                              > > > > > > > > > > This may be caused by refraction. The software
                              > > > > compensates
                              > > > > > for
                              > > > > > > > > > > drift and assures that the correct number of
                              counts
                              > > are
                              > > > > > put
                              > > > > > > into
                              > > > > > > > > > > the table.
                              > > > > > > > > > >
                              > > > > > > > > > > I have had very good luck with changing the drift
                              > > > fitting
                              > > > > > to
                              > > > > > > > > > > a something other than linear, like 5th order.
                              Also
                              > > turn
                              > > >
                              > > > > on
                              > > > > > > > > > > ALL fundementals 1-40 or so. This takes a LONG
                              time
                              > > to
                              > > > > > build
                              > > > > > > > > > > a PE curve but it will follow the wiggles of the
                              > high
                              > > > > order
                              > > > > > > > > > > gears. Overall magnitude of the PE is less of a
                              > > concern
                              > > > > > than
                              > > > > > > > > > > the sort arc-second/second errors.
                              > > > > > > > > > >
                              > > > > > > > > > > -Jason Ware
                              > > > > > > > > > > http://www.galaxyphoto.com
                              > > > > > > > > > >
                              > > > > > > > > > > --- In RCX400@yahoogroups.com, "Brook Risner"
                              > > > > <jegerbekk@>
                              > > > > > > > wrote:
                              > > > > > > > > > > >
                              > > > > > > > > > > > I think I'm getting the hang of PEMpro and
                              > training
                              > > > the
                              > > > > > RCX
                              > > > > > > > > mount.
                              > > > > > > > > > > It looks
                              > > > > > > > > > > > like I am approaching the advertised PE rate of
                              > > less
                              > > > > > than 5
                              > > > > > > > > > > arcsec. PE
                              > > > > > > > > > > > without PEC was initially >32 arcsec peak to
                              peak.
                              >
                              > > > > > After
                              > > > > > > > > building
                              > > > > > > > > > > a curve
                              > > > > > > > > > > > and loading to the mount I got that down to to
                              > > about 7
                              > > >
                              > > > > > > arcsec.
                              > > > > > > > > > > Built
                              > > > > > > > > > > > another curve and refined the first and now it
                              > > looks
                              > > > > > like
                              > > > > > > > about
                              > > > > > > > > 5
                              > > > > > > > > > > arcsec
                              > > > > > > > > > > > peak to peak. (My last session didn't get all
                              the
                              >
                              > > way
                              > > >
                              > > > > > > > through a
                              > > > > > > > > > > full cycle
                              > > > > > > > > > > > before trees block the view of my tracking
                              stars,
                              > > so I
                              > > >
                              > > > > > > don't
                              > > > > > > > > have
                              > > > > > > > > > > full data
                              > > > > > > > > > > > yet) I think I can refine it further and
                              improve
                              > > the
                              > > > > PE
                              > > > > > > even
                              > > > > > > > > > > more. PEMPro
                              > > > > > > > > > > > is the only way to go, in my humble opinion...
                              > > > > > > > > > > >
                              > > > > > > > > > > > I ended up changing the default tracking rate
                              from
                              >
                              > > > > > Sidereal
                              > > > > > > to
                              > > > > > > > > > > Custom -2,
                              > > > > > > > > > > > because PEMPro was showing Y drift in RA, but
                              Dec
                              > > > > didn't
                              > > > > > > look
                              > > > > > > > > like
                              > > > > > > > > > > it was
                              > > > > > > > > > > > drifting. I'm not sure why the tracking rate
                              > would
                              > > be
                              > > >
                              > > > > > off
                              > > > > > > > just
                              > > > > > > > > a
                              > > > > > > > > > > bit, but
                              > > > > > > > > > > > after I adjusted it, the curve was fairly
                              linear.
                              > > > > > > > > > > >
                              > > > > > > > > > > > I've included a link to some screen shots for
                              > > > reference.
                              > > > > > > > > > > >
                              > > > > > > > > > > > http://home.earthlink.net/~jegerbekk/PE%
                              > > 20Results.JPG
                              > > > > > > > > > > >
                              > > > > > > > > > > > I would appreciate any comments or to hear of
                              > > results
                              > > > > > > others
                              > > > > > > > are
                              > > > > > > > > > > getting.
                              > > > > > > > > > > >
                              > > > > > > > > > > > Thanks,
                              > > > > > > > > > > > Brook
                              > > > > > > > > > > >
                              > > > > > > > > > >
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                              > > > > > > > > > >
                              > > > > > > > > > >
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                            • Ray Gralak
                              Hi Michael, Yes, depending on the part of the sky you point to *effective* sidereal rate will be different because of refraction. So even if you had a perfect
                              Message 14 of 17 , Jun 3, 2006
                              • 0 Attachment
                                Hi Michael,

                                Yes, depending on the part of the sky you point to *effective*
                                sidereal rate will be different because of refraction. So even if you
                                had a perfect mount then you would need to adjust the rate depending
                                on where you are pointing. Some mounts can minimize this error by
                                tracking at the "King's rate" and by adjusting the polar alignment
                                slightly to compensate for refraction.

                                If you would like a software solution, I have been working on a
                                product called UltraTrack that can model these tracking rate errors
                                and adjust the mount rate appropriately for the part of the sky the
                                scope is pointed.

                                -Ray

                                > -----Original Message-----
                                > From: RCX400@yahoogroups.com [mailto:RCX400@yahoogroups.com]
                                > On Behalf Of Michael
                                > Sent: Saturday, June 03, 2006 6:11 AM
                                > To: RCX400@yahoogroups.com
                                > Subject: [RCX400] Re: PE and PEMPro
                                >
                                > Hi Ray,
                                > So let me put this into a perspective I can understand.
                                > No matter how good I get my alignment, I will never eliminate the
                                > drift while aquiring data with PEMPro, is that a correct statement?
                                > If thats the fact, then thats something I can live with. I just
                                don't
                                > want to be chasing a ghost here. I am very impressed with PEMPro's
                                > capabilities. My PE WITHOUT a refinement curve went from 21 seconds
                                > to +8.8/-9.4 with an RMS of 1.962 while set to Linear Drift fitting.

                                > It's even lower, though not substantially using a 5th order fit.
                                > Because the drift readings for this run were X Drift -0.019887 and Y

                                > Drift 0.013626, I never did aquire refinement data because I was
                                > under the impression that these drifts were too great and I've been
                                > occupied with trying to eliminate or at least decrease them before
                                > aquiring more data. If you're telling me that I'm stuck with it no
                                > matter how precise my alignment, I'll just pick up where I left off.
                                > Thoughts?
                                >
                                > Michael
                                >
                                > --- In RCX400@yahoogroups.com, "Ray Gralak" <rgr@...> wrote:
                                > >
                                > > Hi Michael,
                                > >
                                > > Even with perfect tracking and no telescope flexure, there will be
                                > > apparent drift from refraction. The effects of refraction will be
                                in
                                > > both axes (RA and Dec). However, I probably could compensate for
                                > > refraction effects in PEMPro so I will put that into my to-do
                                list.
                                > >
                                > > -Ray
                                > >
                                > > > -----Original Message-----
                                > > > From: RCX400@yahoogroups.com [mailto:RCX400@yahoogroups.com]
                                > > > On Behalf Of Michael
                                > > > Sent: Friday, June 02, 2006 8:56 AM
                                > > > To: RCX400@yahoogroups.com
                                > > > Subject: [RCX400] Re: PE and PEMPro
                                > > >
                                > > > Hi Ray,
                                > > > Yeah, thats a good point... why would tracking rates have to do
                                > > > anything with the Y Axis drift (dec).
                                > > > I must say, this can be awfully frustrating. I really thought I
                                > was
                                > > > at the most optimal alignment I could achive with this system.
                                > > > I still do not understand one thing. Granted, PEMPro is a
                                > sensitive
                                > > > application for measuring movement, but all it's really doing is
                                > > what
                                > > > I did manually, that is, track a star using a CCD camera to
                                > measure
                                > > > drift. So if I manually watch a star stationary in the DEC axis
                                on
                                > > my
                                > > > screen for lets say, 10 minutes, why is PEMPro seeing drift of
                                > 10+
                                > > > seconds in 5 minutes using the same techniques I am??
                                > > > I will try the star trails test, I assume I should do this with
                                > RA
                                > > > PEC turned on, right? Otherwise I will record the PE on the
                                images
                                > > as
                                > > > well.
                                > > >
                                > > > Thank you,
                                > > >
                                > > > Michael
                                > > >
                                > > > --- In RCX400@yahoogroups.com, "Ray Gralak" <rgr@> wrote:
                                > > > >
                                > > > > Hi Michael,
                                > > > >
                                > > > > Dec never moves so it cannot be tracking! It is probably polar
                                > > > > misalignment but other things such as refraction and mount/OTA

                                > > > flexure
                                > > > > will (not "can" - *WILL*) cause drift in both axis. As I
                                said,
                                > > > PEMPro
                                > > > > is very sensitive to centroid movement on the CCD. By the time

                                > you
                                > > > > noticed drift after 25 minutes that could easily have been
                                many
                                > > > > arc-seconds. With RA swinging back and forth I wonder how you
                                > > could
                                > > > > really be sure of how much dec drift occurred?
                                > > > >
                                > > > > So, as I previously said try this experiment: take a long
                                > exposure
                                > >
                                > > > to
                                > > > > see what kind of trails you see, or just two exposures 25
                                > minutes
                                > > > > apart. Then compare the centroids with your favorite CCD
                                > > application
                                > > > > to measure the amount of drift that occurred. Just make sure
                                > you
                                > > > know
                                > > > > which axis of the CCD is declination.
                                > > > >
                                > > > > -Ray Gralak
                                > > > > Author of PEMPro
                                > > > >
                                > > > > > -----Original Message-----
                                > > > > > From: RCX400@yahoogroups.com [mailto:RCX400@yahoogroups.com]

                                > > > > > On Behalf Of Michael
                                > > > > > Sent: Friday, June 02, 2006 4:32 AM
                                > > > > > To: RCX400@yahoogroups.com
                                > > > > > Subject: [RCX400] Re: PE and PEMPro
                                > > > > >
                                > > > > > Hi Jason,
                                > > > > >
                                > > > > > Well, Like I said, I drift aligned the scope with the CCD
                                and
                                > > > Maxim
                                > > > > > DL for nearly 25 minutes until I noticed drift. That was
                                > > unguided.
                                > > > > Of
                                > > > > > course the RA was all over the place with PE turned off but
                                > the
                                > > > star
                                > > > >
                                > > > > > doesn't drift within 5-10 minutes time.
                                > > > > > That's why I am asking why PEMPro shows drift?
                                > > > > > Could it be the tracking rate, same as Brooks problem?
                                > > > > >
                                > > > > > Thanks,
                                > > > > >
                                > > > > > Michael
                                > > > > >
                                > > > > > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@>
                                wrote:
                                > > > > > >
                                > > > > > >
                                > > > > > >
                                > > > > > > Here is a simple test. Instead of pempro, just take a
                                series
                                > > > > > > of exposures in MaxIm and see if the star drifts in dec.
                                > > > > > >
                                > > > > > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@>
                                > wrote:
                                > > > > > > >
                                > > > > > > > To be honest, I have a little of what Brooks got... this

                                > new
                                > >
                                > > > > > > > obsession with PEMPro to produce the best PE possible on

                                > my
                                > > > RCX.
                                > > > > > > > When I initially used the software, I was surprised at
                                > the
                                > > > > > > unusually
                                > > > > > > > low PE it had from the beginning. I think it was because

                                > of
                                > > > Dr.
                                > > > > > > Clays
                                > > > > > > > work on the scope, PE peak 2 peak was <21 sec.
                                > > > > > > > But I noticed too that the DEC drift was off.. Brook, I
                                > saw
                                > > > that
                                > > > >
                                > > > > > > same
                                > > > > > > > refinement article on the RCX and saw that my DEC drift
                                > was
                                > > > > worse
                                > > > > > > > than what was in that article and he called HIS
                                > substantial!
                                > >
                                > > > > > > That's
                                > > > > > > > where I got hooked on the PEMPro data.
                                > > > > > > > I began a 3 day campaign on achieving the best polar
                                > > > alignment
                                > > > > > > > possible with what I had. I figured if the PE was that
                                > low,
                                > > > > > > imagine
                                > > > > > > > when the alignment was right on!
                                > > > > > > > Well, I drifted it with a 4mm reticle (9mm w/ barlow)
                                > until
                                > > I
                                > > > > > > noticed
                                > > > > > > > no drift for 15-20 minutes.
                                > > > > > > > Then I drifted with the ST2k at F8 until again, no drift

                                > for
                                > >
                                > > > 15-
                                > > > > > 20
                                > > > > > > > minutes, actually, while doing the east/west, I didn't
                                > get
                                > > > any
                                > > > > > > drift
                                > > > > > > > until after 25 minutes.
                                > > > > > > > I began acquiring data on PEMPro in the same area of sky

                                > I
                                > > > began
                                > > > >
                                > > > > > > e/w
                                > > > > > > > drifting so flexure of any component would have been the

                                > > > same.
                                > > > > > > > The first 5 minutes of PEMPro data shows 10 seconds of
                                > +DEC
                                > > > > > drift.
                                > > > > > > >
                                > > > > > > >
                                > > > > > > > --- In RCX400@yahoogroups.com, "galaxy_jason" <jasone@>
                                > > wrote:
                                > > > > > > > >
                                > > > > > > > >
                                > > > > > > > > Was the CCD attached when you were doing the dec
                                drift?
                                > > Were
                                > > > > > > > > you doing the manual drift in the same part of the sky

                                > as
                                > > > > > > > > the PEMpro run?
                                > > > > > > > >
                                > > > > > > > > Changing the instrument package or slewing to a
                                > different
                                > > > > > > > > part of the sky is enough to change the alignment
                                > slightly
                                > > > > > > > > due to mount flexure.
                                > > > > > > > >
                                > > > > > > > >
                                > > > > > > > > --- In RCX400@yahoogroups.com, "Michael" <mrscheider@>

                                > > > wrote:
                                > > > > > > > > >
                                > > > > > > > > > Hi Brook and Jason,
                                > > > > > > > > > If I can just chime in here for a second regarding
                                the
                                > > > > PEMPro
                                > > > > > > > drift
                                > > > > > > > > > as well?
                                > > > > > > > > > I was concerned while doing an aquision because I
                                > > noticed
                                > > > a
                                > > > > > > very
                                > > > > > > > > high
                                > > > > > > > > > degree of drift on my DEC axis as well... I couldn't

                                > > > figure
                                > > > > > it
                                > > > > > > > out.
                                > > > > > > > > > My manual drift alignment procedures kept a star
                                > > centered
                                > > > on
                                > > > >
                                > > > > > > the
                                > > > > > > > > DEC
                                > > > > > > > > > axis for 15-20 minutes before it moves a few arc
                                > seconds
                                > >
                                > > > but
                                > > > >
                                > > > > > > the
                                > > > > > > > > > first 5 minutes of PEMPro data aquisition showed me
                                > > almost
                                > > > > 10
                                > > > > > > arc
                                > > > > > > > > > seconds of DEC (Y axis) drift.
                                > > > > > > > > > Why am I seeing this kind of drift when my scopes
                                > > > alignment
                                > > > > > > > appears
                                > > > > > > > > > to be so precise?
                                > > > > > > > > > Is this tracking modification Brook spoke of
                                > something I
                                > >
                                > > > > > > should
                                > > > > > > > > > consider changing as well?
                                > > > > > > > > >
                                > > > > > > > > > Best Regards,
                                > > > > > > > > >
                                > > > > > > > > > Michael
                                > > > > > > > > >
                                > > > > > > > > >
                                > > > > > > > > > --- In RCX400@yahoogroups.com, "Brook Risner"
                                > > > <jegerbekk@>
                                > > > > > > wrote:
                                > > > > > > > > > >
                                > > > > > > > > > > Thanks Jason.
                                > > > > > > > > > >
                                > > > > > > > > > > I think I did settle on 5th Order as well. I'll
                                > try
                                > > > the
                                > > > > > tip
                                > > > > > > on
                                > > > > > > > > > using all
                                > > > > > > > > > > fundamentals, do you just use whole numbers, or do

                                > you
                                > >
                                > > > go
                                > > > > > > for
                                > > > > > > > > some
                                > > > > > > > > > fractions
                                > > > > > > > > > > too?
                                > > > > > > > > > >
                                > > > > > > > > > > Changing the tracking rate was kind of a last
                                > resort.
                                > >
                                > > > > > After
                                > > > > > > I
                                > > > > > > > > had
                                > > > > > > > > > gone
                                > > > > > > > > > > through the refine process and loaded the new
                                curve
                                > to
                                > >
                                > > > the
                                > > > >
                                > > > > > > > scope
                                > > > > > > > > I
                                > > > > > > > > > still had
                                > > > > > > > > > > "drift". I first set it to custom rate to -5 and
                                > > that
                                > > > > was
                                > > > > > > too
                                > > > > > > > > > much as I
                                > > > > > > > > > > saw right away that the drift went in the other
                                > > > direction.
                                > > > >
                                > > > > > > I
                                > > > > > > > > > changed it to
                                > > > > > > > > > > -2 and voila, practically linear. I'll have to
                                > > > experiment
                                > > > >
                                > > > > > > with
                                > > > > > > > > > this some
                                > > > > > > > > > > more...
                                > > > > > > > > > >
                                > > > > > > > > > > BTW, what kind of PE are you able to obtain?
                                > > > > > > > > > >
                                > > > > > > > > > > Somehow I'm finding this fun...
                                > > > > > > > > > >
                                > > > > > > > > > > - Brook
                                > > > > > > > > > >
                                > > > > > > > > > >
                                > > > > > > > > > > On 5/31/06, galaxy_jason <jasone@> wrote:
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > > you should not have to do any adjustments to the
                                > > > > tracking
                                > > > > > > > rate.
                                > > > > > > > > > > > This may be caused by refraction. The software
                                > > > > > compensates
                                > > > > > > for
                                > > > > > > > > > > > drift and assures that the correct number of
                                > counts
                                > > > are
                                > > > > > > put
                                > > > > > > > into
                                > > > > > > > > > > > the table.
                                > > > > > > > > > > >
                                > > > > > > > > > > > I have had very good luck with changing the
                                drift
                                > > > > fitting
                                > > > > > > to
                                > > > > > > > > > > > a something other than linear, like 5th order.
                                > Also
                                > > > turn
                                > > > >
                                > > > > > on
                                > > > > > > > > > > > ALL fundementals 1-40 or so. This takes a LONG
                                > time
                                > > > to
                                > > > > > > build
                                > > > > > > > > > > > a PE curve but it will follow the wiggles of the
                                > > high
                                > > > > > order
                                > > > > > > > > > > > gears. Overall magnitude of the PE is less of a
                                > > > concern
                                > > > > > > than
                                > > > > > > > > > > > the sort arc-second/second errors.
                                > > > > > > > > > > >
                                > > > > > > > > > > > -Jason Ware
                                > > > > > > > > > > > http://www.galaxyphoto.com
                                > > > > > > > > > > >
                                > > > > > > > > > > > --- In RCX400@yahoogroups.com, "Brook Risner"
                                > > > > > <jegerbekk@>
                                > > > > > > > > wrote:
                                > > > > > > > > > > > >
                                > > > > > > > > > > > > I think I'm getting the hang of PEMpro and
                                > > training
                                > > > > the
                                > > > > > > RCX
                                > > > > > > > > > mount.
                                > > > > > > > > > > > It looks
                                > > > > > > > > > > > > like I am approaching the advertised PE rate
                                of
                                > > > less
                                > > > > > > than 5
                                > > > > > > > > > > > arcsec. PE
                                > > > > > > > > > > > > without PEC was initially >32 arcsec peak to
                                > peak.
                                > >
                                > > > > > > After
                                > > > > > > > > > building
                                > > > > > > > > > > > a curve
                                > > > > > > > > > > > > and loading to the mount I got that down to to

                                > > > about 7
                                > > > >
                                > > > > > > > arcsec.
                                > > > > > > > > > > > Built
                                > > > > > > > > > > > > another curve and refined the first and now it

                                > > > looks
                                > > > > > > like
                                > > > > > > > > about
                                > > > > > > > > > 5
                                > > > > > > > > > > > arcsec
                                > > > > > > > > > > > > peak to peak. (My last session didn't get all

                                > the
                                > >
                                > > > way
                                > > > >
                                > > > > > > > > through a
                                > > > > > > > > > > > full cycle
                                > > > > > > > > > > > > before trees block the view of my tracking
                                > stars,
                                > > > so I
                                > > > >
                                > > > > > > > don't
                                > > > > > > > > > have
                                > > > > > > > > > > > full data
                                > > > > > > > > > > > > yet) I think I can refine it further and
                                > improve
                                > > > the
                                > > > > > PE
                                > > > > > > > even
                                > > > > > > > > > > > more. PEMPro
                                > > > > > > > > > > > > is the only way to go, in my humble opinion...
                                > > > > > > > > > > > >
                                > > > > > > > > > > > > I ended up changing the default tracking rate
                                > from
                                > >
                                > > > > > > Sidereal
                                > > > > > > > to
                                > > > > > > > > > > > Custom -2,
                                > > > > > > > > > > > > because PEMPro was showing Y drift in RA, but
                                > Dec
                                > > > > > didn't
                                > > > > > > > look
                                > > > > > > > > > like
                                > > > > > > > > > > > it was
                                > > > > > > > > > > > > drifting. I'm not sure why the tracking rate
                                > > would
                                > > > be
                                > > > >
                                > > > > > > off
                                > > > > > > > > just
                                > > > > > > > > > a
                                > > > > > > > > > > > bit, but
                                > > > > > > > > > > > > after I adjusted it, the curve was fairly
                                > linear.
                                > > > > > > > > > > > >
                                > > > > > > > > > > > > I've included a link to some screen shots for
                                > > > > reference.
                                > > > > > > > > > > > >
                                > > > > > > > > > > > > http://home.earthlink.net/~jegerbekk/PE%
                                > > > 20Results.JPG
                                > > > > > > > > > > > >
                                > > > > > > > > > > > > I would appreciate any comments or to hear of
                                > > > results
                                > > > > > > > others
                                > > > > > > > > are
                                > > > > > > > > > > > getting.
                                > > > > > > > > > > > >
                                > > > > > > > > > > > > Thanks,
                                > > > > > > > > > > > > Brook
                                > > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > > Yahoo! Groups Links
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > > >
                                > > > > > > > > > >
                                > > > > > > > > >
                                > > > > > > > >
                                > > > > > > >
                                > > > > > >
                                > > > > >
                                > > > > >
                                > > > > >
                                > > > > >
                                > > > > >
                                > > > > >
                                > > > > >
                                > > > > >
                                > > > > >
                                > > > > >
                                > > > > > SPONSORED LINKS
                                > > > > > Telescope
                                > > > > >
                                <http://groups.yahoo.com/gads?t=ms&k=Telescope&w1=Telescope&w2
                                > > > > >
                                =Buy+telescope&w3=Meade+telescopes&w4=Telescope+eyepieces&w5=D
                                > > > > iscount+telescope&w6=Astronomy+telescope&c=6&s=130>
                                > > > > &.sig=oJI1EMyhfxHvF_MmrTjwnA> Buy telescope
                                > > > > >
                                <http://groups.yahoo.com/gads?t=ms&k=Buy+telescope&w1=Telescop
                                > > > >
                                > e&w2=Buy+telescope&w3=Meade+telescopes&w4=Telescope+eyepieces&w5>
                                > > > > =Discount+telescope&w6=Astronomy+telescope&c=6&s=130&.sig=4JBy
                                > > > > > SamtIlMenLXWZlG4MQ> Meade telescopes
                                > > > > >
                                <http://groups.yahoo.com/gads?t=ms&k=Meade+telescopes&w1=Teles
                                > > > > cope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                > > > > =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                > > > > ope&c=6&s=130&.sig=O4knfrz5RLaQkYzf5Hntfw>
                                > > > > > Telescope eyepieces
                                > > > > >
                                <http://groups.yahoo.com/gads?t=ms&k=Telescope+eyepieces&w1=Te
                                > > > > lescope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                > > > > =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                > > > > ope&c=6&s=130&.sig=2BCoGnXnc1mgh3aietRNLw> Discount
                                > > > > telescope
                                > > > > >
                                <http://groups.yahoo.com/gads?t=ms&k=Discount+telescope&w1=Tel
                                > > > > escope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                > > > > =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                > > > > ope&c=6&s=130&.sig=yvmygrSzRTu2jC0qiibiSQ> Astronomy
                                > > > > telescope
                                > > > > >
                                <http://groups.yahoo.com/gads?t=ms&k=Astronomy+telescope&w1=Te
                                > > > > lescope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                > > > > =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                > > > > ope&c=6&s=130&.sig=OccqLWmO-ZRFSvRNoTqw-A>
                                > > > > >
                                > > > > > ________________________________
                                > > > > >
                                > > > > > YAHOO! GROUPS LINKS
                                > > > > >
                                > > > > >
                                > > > > >
                                > > > > > * Visit your group "RCX400
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                                > > > > >
                                > > > > > * To unsubscribe from this group, send an email to:
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                                > > > > > <mailto:RCX400-unsubscribe@yahoogroups.com?
                                > subject=Unsubscribe>
                                > > > > >
                                > > > > > * Your use of Yahoo! Groups is subject to the Yahoo!
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                                > > > > >
                                > > > > >
                                > > > > > ________________________________
                                > > > > >
                                > > > > >
                                > > > >
                                > > >
                                > > >
                                > > >
                                > > >
                                > > >
                                > > >
                                > > >
                                > > >
                                > > >
                                > > >
                                > > >
                                > > > SPONSORED LINKS
                                > > > Telescope
                                > > > <http://groups.yahoo.com/gads?t=ms&k=Telescope&w1=Telescope&w2
                                > > > =Buy+telescope&w3=Meade+telescopes&w4=Telescope+eyepieces&w5=D
                                > > iscount+telescope&w6=Astronomy+telescope&c=6&s=130>
                                > > &.sig=oJI1EMyhfxHvF_MmrTjwnA> Buy telescope
                                > > > <http://groups.yahoo.com/gads?t=ms&k=Buy+telescope&w1=Telescop
                                > > e&w2=Buy+telescope&w3=Meade+telescopes&w4=Telescope+eyepieces&w5>
                                > > =Discount+telescope&w6=Astronomy+telescope&c=6&s=130&.sig=4JBy
                                > > > SamtIlMenLXWZlG4MQ> Meade telescopes
                                > > > <http://groups.yahoo.com/gads?t=ms&k=Meade+telescopes&w1=Teles
                                > > cope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                > > =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                > > ope&c=6&s=130&.sig=O4knfrz5RLaQkYzf5Hntfw>
                                > > > Telescope eyepieces
                                > > > <http://groups.yahoo.com/gads?t=ms&k=Telescope+eyepieces&w1=Te
                                > > lescope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                > > =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                > > ope&c=6&s=130&.sig=2BCoGnXnc1mgh3aietRNLw> Discount
                                > > telescope
                                > > > <http://groups.yahoo.com/gads?t=ms&k=Discount+telescope&w1=Tel
                                > > escope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                > > =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                > > ope&c=6&s=130&.sig=yvmygrSzRTu2jC0qiibiSQ> Astronomy
                                > > telescope
                                > > > <http://groups.yahoo.com/gads?t=ms&k=Astronomy+telescope&w1=Te
                                > > lescope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                > > =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                > > ope&c=6&s=130&.sig=OccqLWmO-ZRFSvRNoTqw-A>
                                > > >
                                > > > ________________________________
                                > > >
                                > > > YAHOO! GROUPS LINKS
                                > > >
                                > > >
                                > > >
                                > > > * Visit your group "RCX400
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                                > > >
                                > > > * To unsubscribe from this group, send an email to:
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                                > > >
                                > >
                                >
                                >
                                >
                                >
                                >
                                >
                                >
                                >
                                >
                                >
                                > SPONSORED LINKS
                                > Telescope
                                > <http://groups.yahoo.com/gads?t=ms&k=Telescope&w1=Telescope&w2
                                > =Buy+telescope&w3=Meade+telescopes&w4=Telescope+eyepieces&w5=D
                                iscount+telescope&w6=Astronomy+telescope&c=6&s=130>
                                &.sig=oJI1EMyhfxHvF_MmrTjwnA> Buy telescope
                                > <http://groups.yahoo.com/gads?t=ms&k=Buy+telescope&w1=Telescop
                                e&w2=Buy+telescope&w3=Meade+telescopes&w4=Telescope+eyepieces&w5>
                                =Discount+telescope&w6=Astronomy+telescope&c=6&s=130&.sig=4JBy
                                > SamtIlMenLXWZlG4MQ> Meade telescopes
                                > <http://groups.yahoo.com/gads?t=ms&k=Meade+telescopes&w1=Teles
                                cope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                ope&c=6&s=130&.sig=O4knfrz5RLaQkYzf5Hntfw>
                                > Telescope eyepieces
                                > <http://groups.yahoo.com/gads?t=ms&k=Telescope+eyepieces&w1=Te
                                lescope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                ope&c=6&s=130&.sig=2BCoGnXnc1mgh3aietRNLw> Discount > telescope
                                > <http://groups.yahoo.com/gads?t=ms&k=Discount+telescope&w1=Tel
                                escope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                ope&c=6&s=130&.sig=yvmygrSzRTu2jC0qiibiSQ> Astronomy > telescope
                                > <http://groups.yahoo.com/gads?t=ms&k=Astronomy+telescope&w1=Te
                                lescope&w2=Buy+telescope&w3=Meade+telescopes&w4>
                                =Telescope+eyepieces&w5=Discount+telescope&w6=Astronomy+telesc
                                ope&c=6&s=130&.sig=OccqLWmO-ZRFSvRNoTqw-A>
                                >
                                > ________________________________
                                >
                                > YAHOO! GROUPS LINKS
                                >
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                                >
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