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90-day SSN data for HamCAP

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  • bill_w4zv
    Alex or anyone: HamCAP apparently wants the 90-day smoothed sunspot number in the Parameters screen. I can t seem to find that on any of the NOAA databases.
    Message 1 of 17 , Apr 8 6:26 AM
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      Alex or anyone:

      HamCAP apparently wants the 90-day smoothed sunspot number in the
      Parameters screen. I can't seem to find that on any of the NOAA
      databases. Is it the same as the projected number on the following
      graph for the current month? It's not clear to me what period they
      are smoothing over for this graph.

      http://www.sel.noaa.gov/ftpdir/weekly/sunspot.gif

      If I am interpolating correctly, the current smoothed SSN is about 20.
      Is that the correct number to input to HamCAP?

      73, Bill W4ZV
    • Pete Smith
      Good question -- I see that IonoProbe displays a value for this parameter -- currently 47, not 20. I, too, could not find a source for the 90-day I average.
      Message 2 of 17 , Apr 8 10:33 AM
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        Good question -- I see that IonoProbe displays a value for this parameter
        -- currently 47, not 20. I, too, could not find a source for the 90-day I
        average. Iam not sure if it is downloaded or automatically calculated from
        the daily numbers provided in one or another of the standard reports. I
        did note, though, that if you have IonoProbe, it automatically links with
        Hamcap to provide the necessary updated number.

        73, Pete N4ZR

        At 09:26 AM 4/8/2005, bill_w4zv wrote:



        >Alex or anyone:
        >
        >HamCAP apparently wants the 90-day smoothed sunspot number in the
        >Parameters screen. I can't seem to find that on any of the NOAA
        >databases. Is it the same as the projected number on the following
        >graph for the current month? It's not clear to me what period they
        >are smoothing over for this graph.
        >
        >http://www.sel.noaa.gov/ftpdir/weekly/sunspot.gif
        >
        >If I am interpolating correctly, the current smoothed SSN is about 20.
        > Is that the correct number to input to HamCAP?
        >
        >73, Bill W4ZV
        >
        >
        >
        >
        >
        >
        >Yahoo! Groups Links
        >
        >
        >
        >
      • Alex, VE3NEA
        Since HamCap is just a front end to VOACAP, you should use the same parameters with this program as you would use with VOACAP itself. VOACAP expects the
        Message 3 of 17 , Apr 8 2:07 PM
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          Since HamCap is just a front end to VOACAP, you should use the same
          parameters with this program as you would use with VOACAP itself.

          VOACAP expects the 13-month average SSN which can be found, in particular,
          at
          ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/SMOOTHED/

          Unfortunately, this index if published with a 6-month lag due to averaging.
          Unless you want to see what the propagation was half a year ago, you should
          use some other SSN index that is close enough to the 13-month average but is
          available for the current month.

          One possible solution to this problem is to use the predicted smoothed SSN
          that NOAA publishes at
          ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/SUNSPOT.LST
          Keep in mind, however, that these predictions are not always accurate.
          HamCap has a list of such predictions, published at the time of program
          release, in the file called SSN.dat. These data are used to populate the SSN
          box in the program when the month changes. You can open the file in Notepad
          and compare its content to the current NOAA predictions.

          Another solution that I like more is to use the 90-day SSN that IonoProbe
          calculates by averaging the daily SSN over the last 3 months (you may have
          to use the Download Old Data command in the program to ensure that enough
          daily data are available).

          73 Alex VE3NEA




          >
          > Good question -- I see that IonoProbe displays a value for this parameter
          > -- currently 47, not 20. I, too, could not find a source for the 90-day I
          > average. Iam not sure if it is downloaded or automatically calculated
          from
          > the daily numbers provided in one or another of the standard reports. I
          > did note, though, that if you have IonoProbe, it automatically links with
          > Hamcap to provide the necessary updated number.
          >
          > 73, Pete N4ZR
          >
          > At 09:26 AM 4/8/2005, bill_w4zv wrote:
          >
          >
          >
          > >Alex or anyone:
          > >
          > >HamCAP apparently wants the 90-day smoothed sunspot number in the
          > >Parameters screen. I can't seem to find that on any of the NOAA
          > >databases. Is it the same as the projected number on the following
          > >graph for the current month? It's not clear to me what period they
          > >are smoothing over for this graph.
          > >
          > >http://www.sel.noaa.gov/ftpdir/weekly/sunspot.gif
          > >
          > >If I am interpolating correctly, the current smoothed SSN is about 20.
          > > Is that the correct number to input to HamCAP?
          > >
          > >73, Bill W4ZV
        • Bob Lafont
          Alex, I am trying to find out how to upgrade my version of DX Atlas from v1.5 to 2.25. I followed the instructions on the DX Atlas web site and sent an email
          Message 4 of 17 , Apr 8 4:37 PM
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            Alex,

            I am trying to find out how to upgrade my version of DX Atlas from v1.5 to
            2.25.

            I followed the instructions on the DX Atlas web site and sent an email with
            my registration info but haven't heard anything back.

            Can you help me find out what I need to do to upgrade?

            Thanks


            73-Bob
            WA2MNO






            [Non-text portions of this message have been removed]
          • Pete Smith
            I think the thing that is confusing Bill (and me, for that matter) is the large divergence between the various sunspot numbers available to plug into Ham Cap.
            Message 5 of 17 , Apr 9 4:00 AM
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              I think the thing that is confusing Bill (and me, for that matter) is the
              large divergence between the various sunspot numbers available to plug into
              Ham Cap. For example, for April 2005:

              Ham Cap's built-in number (old NOAA predicted): 30
              Current NOAA predicted smoothed SSN: 28.5 (pretty close)
              IonoProbe's computed 90-day smoothed SSN: 47 (!)

              The difference in the outcome is meaningful -- for example, with the SSN at
              30, for my short path to 3B8, 15 M opens only briefly, although there is a
              long period when the MUF is predicted to be right below 15. With the SSN
              set at 47, 15M is predicted to be open for essentially the same fairly long
              period, and a second night-time 20M opening is also predicted.

              Like Alex, I think I prefer IonoProbe's number, not because of the outcome
              but because it seems to reflect what is more currently happening than a
              projection from 6 months ago. On the other hand, I understand that VOACAP
              is really built around the 13-month number, so during a period when the
              90-day number diverges substantially upward from the 13-month average, the
              predictions may be unduly rosy.

              While we're on the subject, a question I have wondered about -- why do Ham
              Cap's charts not have a graduated hour scale on the X axis? Have I missed
              an option to turn them on?

              73, Pete N4ZR


              At 05:07 PM 4/8/2005, Alex, VE3NEA wrote:


              >Since HamCap is just a front end to VOACAP, you should use the same
              >parameters with this program as you would use with VOACAP itself.
              >
              >VOACAP expects the 13-month average SSN which can be found, in particular,
              >at
              >ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/SMOOTHED/
              >
              >Unfortunately, this index if published with a 6-month lag due to averaging.
              >Unless you want to see what the propagation was half a year ago, you should
              >use some other SSN index that is close enough to the 13-month average but is
              >available for the current month.
              >
              >One possible solution to this problem is to use the predicted smoothed SSN
              >that NOAA publishes at
              >ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/SUNSPOT.LST
              >Keep in mind, however, that these predictions are not always accurate.
              >HamCap has a list of such predictions, published at the time of program
              >release, in the file called SSN.dat. These data are used to populate the SSN
              >box in the program when the month changes. You can open the file in Notepad
              >and compare its content to the current NOAA predictions.
              >
              >Another solution that I like more is to use the 90-day SSN that IonoProbe
              >calculates by averaging the daily SSN over the last 3 months (you may have
              >to use the Download Old Data command in the program to ensure that enough
              >daily data are available).
              >
              >73 Alex VE3NEA
              >
              >
              >
              >
              > >
              > > Good question -- I see that IonoProbe displays a value for this parameter
              > > -- currently 47, not 20. I, too, could not find a source for the 90-day I
              > > average. Iam not sure if it is downloaded or automatically calculated
              >from
              > > the daily numbers provided in one or another of the standard reports. I
              > > did note, though, that if you have IonoProbe, it automatically links with
              > > Hamcap to provide the necessary updated number.
              > >
              > > 73, Pete N4ZR
              > >
              > > At 09:26 AM 4/8/2005, bill_w4zv wrote:
              > >
              > >
              > >
              > > >Alex or anyone:
              > > >
              > > >HamCAP apparently wants the 90-day smoothed sunspot number in the
              > > >Parameters screen. I can't seem to find that on any of the NOAA
              > > >databases. Is it the same as the projected number on the following
              > > >graph for the current month? It's not clear to me what period they
              > > >are smoothing over for this graph.
              > > >
              > > >http://www.sel.noaa.gov/ftpdir/weekly/sunspot.gif
              > > >
              > > >If I am interpolating correctly, the current smoothed SSN is about 20.
              > > > Is that the correct number to input to HamCAP?
              > > >
              > > >73, Bill W4ZV
              >
              >
              >
              >
              >Yahoo! Groups Links
              >
              >
              >
              >
            • bill_w4zv
              ... is the ... plug into ... Yet the average montthly sunspots for the past 3 months are: 2005 01 31.3 2005 02 29.1 2005 03 24.8 Average = 28.4, which is
              Message 6 of 17 , Apr 9 5:29 AM
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                --- In dxatlas_group@yahoogroups.com, Pete Smith <n4zr@c...> wrote:
                > I think the thing that is confusing Bill (and me, for that matter)
                is the
                > large divergence between the various sunspot numbers available to
                plug into
                > Ham Cap. For example, for April 2005:
                >
                > Ham Cap's built-in number (old NOAA predicted): 30
                > Current NOAA predicted smoothed SSN: 28.5 (pretty close)
                > IonoProbe's computed 90-day smoothed SSN: 47 (!)

                Yet the average montthly sunspots for the past 3 months are:

                2005 01 31.3
                2005 02 29.1
                2005 03 24.8

                Average = 28.4, which is very close to the built-in 30 and current
                NOAA predicted 28.5.

                ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/MONTHLY.PLT

                How can IonoProbe's computed 90-day SSN possibly be 47? This is
                different by nearly a factor of two!

                73, Bill
              • bill_w4zv
                ... Could IonoProbe s calculation be off by one year? I notice 47 is very close to the SSN numbers for this time last year: 2004 52.0 49.3 47.1 45.6
                Message 7 of 17 , Apr 9 5:40 AM
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                  I wrote:

                  > How can IonoProbe's computed 90-day SSN possibly be 47? This is
                  > different by nearly a factor of two!

                  Could IonoProbe's calculation be off by one year? I notice 47 is very
                  close to the SSN numbers for this time last year:

                  2004 52.0 49.3 47.1 45.6 43.9 41.7 40.2 39.2 37.5

                  ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/SMOOTHED

                  And the average of 49.3, 47.1, and 45.6 is 47.3. Maybe the logic of
                  the calculation has an error somewhere in its data collection.

                  73, Bill (...using 29 for now)
                • Pete Smith
                  Bill, aren t those numbers predicted from 6 months ago? I looked at the graphed SSNs for the last three months from IonoProbe and they seem much more
                  Message 8 of 17 , Apr 9 6:10 AM
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                    Bill, aren't those numbers predicted from 6 months ago? I looked at the
                    graphed SSNs for the last three months from IonoProbe and they seem much
                    more consistent with the 47 average.

                    73, Pete

                    At 08:29 AM 4/9/2005, bill_w4zv wrote:



                    >--- In dxatlas_group@yahoogroups.com, Pete Smith <n4zr@c...> wrote:
                    > > I think the thing that is confusing Bill (and me, for that matter)
                    >is the
                    > > large divergence between the various sunspot numbers available to
                    >plug into
                    > > Ham Cap. For example, for April 2005:
                    > >
                    > > Ham Cap's built-in number (old NOAA predicted): 30
                    > > Current NOAA predicted smoothed SSN: 28.5 (pretty close)
                    > > IonoProbe's computed 90-day smoothed SSN: 47 (!)
                    >
                    >Yet the average montthly sunspots for the past 3 months are:
                    >
                    >2005 01 31.3
                    >2005 02 29.1
                    >2005 03 24.8
                    >
                    >Average = 28.4, which is very close to the built-in 30 and current
                    >NOAA predicted 28.5.
                    >
                    >ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/MONTHLY.PLT
                    >
                    >How can IonoProbe's computed 90-day SSN possibly be 47? This is
                    >different by nearly a factor of two!
                    >
                    >73, Bill
                    >
                    >
                    >
                    >
                    >
                    >
                    >Yahoo! Groups Links
                    >
                    >
                    >
                    >
                  • bill_w4zv
                    ... Definitely so. The current 90 day average (1 Jan 05 - 31 Mar 05) is 28.4 using this data:
                    Message 9 of 17 , Apr 9 6:12 AM
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                      I wrote:

                      > Maybe the logic of
                      > the calculation has an error somewhere in its data collection.

                      Definitely so. The current 90 day average (1 Jan 05 - 31 Mar 05) is
                      28.4 using this data:

                      ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/RIDAILY.PLT

                      I don't have IonoProbe, but it must have a problem if the 47 number
                      Pete quoted for the IonoProbe calculation is correct. Anyhow, now I
                      know what to use and will probably just go with the NOAA forecast
                      which seems to be fairly accurate at this stage of the cycle.

                      73, Bill
                    • Alex, VE3NEA
                      ... I am not sure how monthly values presented on that page are calculated. IonoProbe just averages the last 90 daily values from
                      Message 10 of 17 , Apr 9 9:40 AM
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                        > Yet the average montthly sunspots for the past 3 months are:
                        > 2005 01 31.3
                        > 2005 02 29.1
                        > 2005 03 24.8
                        > Average = 28.4, which is very close to the built-in 30 and current
                        > NOAA predicted 28.5.
                        > ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/MONTHLY.PLT
                        > How can IonoProbe's computed 90-day SSN possibly be 47? This is
                        > different by nearly a factor of two!

                        I am not sure how monthly values presented on that page are calculated.
                        IonoProbe just averages the last 90 daily values from
                        http://www.sec.noaa.gov/ftpdir/latest/DSD.txt and
                        http://www.sec.noaa.gov/ftpdir/indices/old_indices/




                        > Could IonoProbe's calculation be off by one year? I notice 47 is very
                        > close to the SSN numbers for this time last year:
                        > 2004 52.0 49.3 47.1 45.6 43.9 41.7 40.2 39.2 37.5
                        > ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/SMOOTHED
                        > And the average of 49.3, 47.1, and 45.6 is 47.3. Maybe the logic of
                        > the calculation has an error somewhere in its data collection.

                        IonoProbe does not have access to the data from the last year.


                        > Definitely so. The current 90 day average (1 Jan 05 - 31 Mar 05) is
                        > 28.4 using this data:
                        > ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/RIDAILY.PLT

                        These are the RI indices, not daily SSN values.



                        > Anyhow, now I
                        > know what to use and will probably just go with the NOAA forecast
                        > which seems to be fairly accurate at this stage of the cycle.

                        You may want to enter the latest NOAA forecasts in the SSN.dat file using
                        Notepad, then HamCap will use these data automatically.


                        73 Alex VE3NEA
                      • Bob Lafont
                        Has anyone upgraded DX Atlas from 1.x to 2.x ? And if you have how did you go about getting the upgrade? 73-Bob WA2MNO [Non-text portions of this message have
                        Message 11 of 17 , Apr 9 9:47 AM
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                          Has anyone upgraded DX Atlas from 1.x to 2.x ?

                          And if you have how did you go about getting the upgrade?



                          73-Bob
                          WA2MNO






                          [Non-text portions of this message have been removed]
                        • Alex, VE3NEA
                          ... HamCap is an interactive application. When you move the mouse cursor over the chart, the time and all other parameters of the point under the cursor are
                          Message 12 of 17 , Apr 9 9:56 AM
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                            > While we're on the subject, a question I have wondered about -- why do Ham
                            > Cap's charts not have a graduated hour scale on the X axis? Have I missed
                            > an option to turn them on?

                            HamCap is an interactive application. When you move the mouse cursor over
                            the chart, the time and all other parameters of the point under the cursor
                            are displayed on the status bar.

                            I tried to make the HamCap window as small as possible so that it could be
                            used during contesting and DXing when screen space is a valuable resource,
                            so I removed all unnecessary elements form the user interface, including the
                            time scale on the chart.


                            73 Alex VE3NEA
                          • Alex, VE3NEA
                            A while ago I did some comparisons of median SNR predictions from VOACAP to the observations of NCSXF beacons. Ingemar SM5AJV developed a program that measures
                            Message 13 of 17 , Apr 9 10:10 AM
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                              A while ago I did some comparisons of median SNR predictions from VOACAP to
                              the observations of NCSXF beacons. Ingemar SM5AJV developed a program that
                              measures the SNR of beacon signals using a sound card and an FFT
                              transformation. A correlator is used to compare the received waveform to
                              that of the beacon's callsign, to make sure that the signal actually comes
                              from the beacon. Ingemar was kind enough to send me his logs for June 2004,
                              these logs cover about 24% of the month.

                              I developed a viewer utility for the logs that converts the observed SNR
                              values
                              into dB-Hz, calculates medians, and plots both predicted and observed median
                              values along with the observation points for the selected beacon and band.
                              The program lacks a sophisticated user interface, which I may develop in the
                              future if there is sufficient interest. A few screenshots of typical plots
                              are here: http://www.dxatlas.com/Private/SnrPlot.zip .

                              For those who want to play with the viewer, I uploaded it to
                              http://www.dxatlas.com/Private/VoaAnal.zip .
                              The zip file also includes the observation data, with permission
                              from Ingemar. Please preserve the directory structure when unzipping.

                              Though this is just the first alpha version of the program and thus it may
                              contain errors, the plots it produces are very interesting. The shape of the
                              VOACAP prediction chart is very close to that of the observation chart,
                              though the absolute values are way off. On average, VOACAP underestimates
                              the SNR by 20+ dB.

                              Also, these charts explain why the median SNR is a bad indicator of
                              propagation conditions. The median value makes sense only for unimodal
                              distributions, while the distribution of SNR is bi-modal at best (that is,
                              has two or more peaks). One peak is formed by the observations that where
                              performed when the path was open with a good propagation mode, and one or
                              more peaks come from the days when only very lossy modes were available or
                              the path was closed.


                              73 Alex VE3NEA
                            • Pete Smith
                              OK - thanks! Makes sense. 73, Pete
                              Message 14 of 17 , Apr 9 11:27 AM
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                                OK - thanks! Makes sense.

                                73, Pete

                                At 12:56 PM 4/9/2005, Alex, VE3NEA wrote:



                                > > While we're on the subject, a question I have wondered about -- why do Ham
                                > > Cap's charts not have a graduated hour scale on the X axis? Have I missed
                                > > an option to turn them on?
                                >
                                >HamCap is an interactive application. When you move the mouse cursor over
                                >the chart, the time and all other parameters of the point under the cursor
                                >are displayed on the status bar.
                                >
                                >I tried to make the HamCap window as small as possible so that it could be
                                >used during contesting and DXing when screen space is a valuable resource,
                                >so I removed all unnecessary elements form the user interface, including the
                                >time scale on the chart.
                                >
                                >
                                >73 Alex VE3NEA
                                >
                                >
                                >
                                >
                                >
                                >
                                >Yahoo! Groups Links
                                >
                                >
                                >
                                >
                              • Pete Smith
                                [With apologies to readers of the VOACAP list, who are joining this in mid-thread, I feel that Bill and I are floundering fairly far out of our depth in this
                                Message 15 of 17 , Apr 9 11:32 AM
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                                  [With apologies to readers of the VOACAP list, who are joining this in
                                  mid-thread, I feel that Bill and I are floundering fairly far out of our
                                  depth in this discussion that began on the dxatlas list. The question
                                  began as what SSN to use in Ham Cap, a simplified front end for
                                  VOACAP. HamCAP comes with a table of predicted international SSNs, but can
                                  also link with IonoProbe, which downloads daily SSNs from the SEC. VE3NEA,
                                  the author of Ham Cap, prefers the SEC numbers, but the variance from the
                                  international SSns is considerable, with the SEC number typically running
                                  much higher. Any advice appreciated!]

                                  Bill, there's some apples and oranges, or something going on
                                  here. IonoProbe gets its numbers from the Joint USAF/NOAA Solar and
                                  Geophysical Activity Summary. Here's a sample:

                                  "SGAS Number 099 Issued at 0245Z on 09 Apr 2005
                                  This report is compiled from data received at SWO on 08 Apr
                                  A. Energetic Events
                                  Begin Max End Rgn Loc Xray Op 245MHz 10cm Sweep
                                  None
                                  B. Proton Events: None
                                  C. Geomagnetic Activity Summary: The geomagnetic field was quiet.
                                  D. Stratwarm: Not Available
                                  E. Daily Indices: (real-time preliminary/estimated values)
                                  10 cm 088 SSN 056 Afr/Ap 005/004 ...."

                                  Ionoprobe's retrospective record of these reports shows March 12 (chosen
                                  randomly) with a SSN of 67, versus 42 on the table you cite. March 18 is
                                  37 versus 25, and so on.

                                  I have no idea what the explanation is, though I do note that there is
                                  another table, ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/2005
                                  , which gives the numbers just for this year to date and states that
                                  "Values are preliminary after Dec 2004."

                                  There is an interesting explanation of how various sunspot numbers are
                                  calculated in
                                  ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/sunspot.predict. It
                                  seems clear from this explanation that the international sunspot number is
                                  a highly-massaged, worldwide average number that does not become final for
                                  some months after the date of observation. By contrast, the number cited
                                  in the SGAS is the SEC's every-six-hour figure, and must be based strictly
                                  on its own observations. An interesting graph at
                                  http://www.nwra-az.com/spawx/comp.html speaks to this. To quote from the
                                  caption:

                                  " This plot illustrates the differences between the "real" sunspot number
                                  (SSN), which is calculated from optical observations of the sun, a sunspot
                                  number derived from the 10.7cm solar radio flux (SSNf), and a sunspot
                                  number derived from fitting an ionospheric model to ionospheric
                                  measurements. All of these indices are used as inputs to models of the
                                  ionosphere for use in communications-performance predictions - this plot
                                  shows that they don't always agree as to what the SSN should be in that
                                  particular context.

                                  Note: The F10.7-derived SSN (SSNf) is calculated from the 10.7cm solar
                                  radio flux (the Penticton Radio Observatory noon value) using the following
                                  relationship:

                                  F10.7 = 63.74 + 0.727*SSNf + 0.000895*SSNf**2

                                  So, where does this leave us? Where it left me, frankly, is wondering why
                                  we use sunspot numbers at all, rather than solar flux and A/K indices, or
                                  at least the SSNf, which would be closer to the values Bill cited than to
                                  the current high value of optically-observed SSN. On the other hand, Alex
                                  argues that results from using the lower SSNs seem to run consistently low
                                  in terms of predicted vs. observed S/R ratio.

                                  It would be interesting to pass this discussion over to the VOACAP list and
                                  see what the gurus there, particularly including Greg Hand and George Lane,
                                  think of it. In fact, I have done that, and it will be interesting to see
                                  what comes of it.

                                  73, Pete N4ZR



                                  At 09:12 AM 4/9/2005, bill_w4zv wrote:



                                  >I wrote:
                                  >
                                  > > Maybe the logic of
                                  > > the calculation has an error somewhere in its data collection.
                                  >
                                  >Definitely so. The current 90 day average (1 Jan 05 - 31 Mar 05) is
                                  >28.4 using this data:
                                  >
                                  >ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/RIDAILY.PLT
                                  >
                                  >I don't have IonoProbe, but it must have a problem if the 47 number
                                  >Pete quoted for the IonoProbe calculation is correct. Anyhow, now I
                                  >know what to use and will probably just go with the NOAA forecast
                                  >which seems to be fairly accurate at this stage of the cycle.
                                  >
                                  >73, Bill
                                  >
                                  >
                                  >
                                  >
                                  >
                                  >
                                  >Yahoo! Groups Links
                                  >
                                  >
                                  >
                                  >
                                • bill_w4zv
                                  ... wondering why ... I agree. Seems like measured solar flux, which supposedly shows the actual effect of sunspots on the ionosphere, would be better. After
                                  Message 16 of 17 , Apr 10 4:40 AM
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                                    --- In dxatlas_group@yahoogroups.com, Pete Smith <n4zr@c...> wrote:

                                    >
                                    > So, where does this leave us? Where it left me, frankly, is
                                    wondering why
                                    > we use sunspot numbers at all, rather than solar flux and A/K indices,

                                    I agree. Seems like measured solar flux, which supposedly shows the
                                    actual effect of sunspots on the ionosphere, would be better. After
                                    all, when there is a large CME, we often can see little effect on the
                                    ionosphere depending on how it's directed toward Earth, which way Bz
                                    points, etc. Of course if VOACAP was originally based on SSN's, then
                                    maybe they should be the input. Hopefully Greg Hand will respond, and
                                    please post anything of interest here since I am not on that list. No
                                    model is any better than its input..."Garbage In Garbage Out" as
                                    someone said.

                                    73, Bill
                                  • bill_w4zv
                                    I wrote: The current 90 day average (1 Jan 05 - 31 Mar 05) is 28.4 using this data: ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/RIDAILY.PLT VE3NEA
                                    Message 17 of 17 , Apr 10 12:50 PM
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                                      I wrote: The current 90 day average (1 Jan 05 - 31 Mar 05) is
                                      28.4 using this data:
                                      ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/RIDAILY.PLT

                                      VE3NEA wrote: These are the RI indices, not daily SSN values.

                                      Alex, the NOAA site below calls these "Provisional International
                                      Sunspot Numbers, so what do you mean they are not daily SSN numbers?
                                      See especially their comments preceded by ***** below:
                                      ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/sunspot.predict

                                      >The provisional daily Zurich relative sunspot numbers, Rz, were based
                                      upon
                                      observations made at Zurich and its two branch stations in Arosa and
                                      Locarno
                                      and communicated by M. Waldmeier of the Swiss Federal Observatory.
                                      Beginning
                                      January 1, 1981, the Zurich relative sunspot number program is
                                      replaced by
                                      the "Sunspot Index Data Center" (c/o Dr. P. Cugnon, 3 av. Circulaire,
                                      B-1180
                                      Bruxelles, Belgium).


                                      ***** The determination of the provisional International Sunspot
                                      Numbers Ri results from a statistical treatment of the data
                                      originating from more than twenty-five observing stations. These
                                      stations constitute an international network, with the Locarno
                                      (Switzerland) station as the reference station, to guarantee
                                      continuity with the past Zurich series of Rz.*****

                                      >The definitive International Sunspot Numbers Ri are evaluated by a
                                      similar method based on a network of observing stations selected for
                                      their
                                      high number of observations, their continuity during the whole year
                                      and an
                                      existing series of observations during the last years. Also taken into
                                      account is the stability of the K monthly factors with reference to the
                                      Locarno station.

                                      *****These relative sunspot numbers are now designated Ri
                                      (International) instead of Rz (Zurich).*****

                                      It seems to me Ri is exactly what should be used, but am really
                                      waiting to see what Greg Hand, etc. of VOACAP have to say.

                                      73, Bill
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