Bob, 145.825 is the "established" space APRS frequency, and has been/is used by more than just the ISS for years. There are other APRS satellites which are intermittently active on the same frequency, and I expect there will be others in the future. I can't address the formal coordination issue, but anything with an uplink on that frequency is guaranteed to have problems. The only question is whether those problems are tolerable. There is little to no APRS activity on that frequency over most of the world, and then there is the question of both HO-68 and the ISS being in the same footprint. The HO-68 has an inclination of about 102 degrees, the ISS about half that. Finally, the ISS is not active on that frequency 24/7. It operates on other frequencies for voice and SSTV, and is often QRT completely due to other operations. In an imperfect world, it looks like a reasonable tradeoff, though other evaluations are certainly possible.
The problem of unattended APRS beacons does cut both ways. There are some daylight-only APRS satellites. When they enter periods of extended illumination, they can be commanded from their default modes. However, even a single "braaap" can pull the DC busses low enough that the command stations need to start over again. WB4APR has lamented this problem, with specific calls, in other venues. Looking at some of the paths, both in Drew's example and my reception, there are stations whose paths have not been updated for years. The sort of courtesy/coordination issue is not limited to space operations. A ham relatively local to me fired up a propagation beacon on 30 meters this month. It is/was within 200 HZ of an APRS frequency which has been in use for some time. Quite a fight over who "owns" the frequency. ;) Alan WA4SCA _______________________________________________ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
