Re: [tracker2] airborne digi
- James VE6SRV wrote...
> Hey Keith, Pete's callsign is KD0CVN-1Sorry for the slow reply... been a bit hectic the last few days!
> It looks like you might have done some homework... From what I canThere's nothing like having your antenna up 10,000 feet! Even though I'm
> see, you are using a single hop path at most. As you have observed,
> you can get into the APRS network from an airborne platform very
at ground level, I have pretty good success with one and two hop paths.
With a T2, Pete could use profile switching based on altitude. Depending
on terrain, he could use a standard two hop WIDE1-1,WIDE2-1 (or possibly
WIDE2-2 instead) below a certain altitude, and either no path at all or
a one hop WIDE2-1 above a certain altitude. He could also have a switch
to manually force it to the two hop profile if there were occasions
where it was deemed necessary... e.g. an area where the digis and IGates
were really spread out and the mountains were protruding above the
altitude where he normally switched to the one hop profile.
One hop vs no hops... you only have to make it to an IGate for people
tracking the plane via the APRS-IS. Where the IGates are close together,
a plane could be heard direct by a number of IGates at any given time.
Where they are spread out a bit more thinly, a one hop path would at
least double his chances of making it to an IGate as long as there were
some digis around the IGates.
Pete KD0CVN had said...
> I'd like to set up the digi function (mini awacs)...As several people mentioned, having a digi up at 10,000 wouldn't
necessarily be a good thing, unless you were in any area where there
were no digis. You could be hearing signals from a few hundred miles in
each direction, perhaps taking in area of 30,000 to 200,000 square
miles. In many areas, you would be propagating signals much further than
the originator intended, and far outside their ALOHA circle. You could
be forcing users using a sensible two hop path to be spreading their
signals as far as if they had been using a seven hop path. Basically,
except under special circumstances, a regular digi on 144.390 at 10,000
feet would be a bad thing.
73 es cul - Keith VE7GDH
"I may be lost, but I know exactly where I am!"