2014-04-18
Differences in orbits when tracking the ISS
Another ISS pass and I was already aware the orbit may be changing a bit since gpredict and hamsatdroid were disagreeing on the time of the pass. And indeed, the ISS pass started around the later time from gpredict. I heard the AFSK data clearly. The signal from the ISS is strong enough that I can receive it most of the pass with the arrow antenna just pointing directly up. Maybe I can use this to record an entire pass and decode the AFSK data. I guess celestrak.com (used by gpredict by default) is better up to date than amsat.org (first option in hamsatdroid). Since hamsatdroid can also use the celestrak.com data I switched to this source. The fun part is that satellite names aren't the same. 'SO-50' according to amsat is 'SAUDISAT 1C (SO-50)' according to celestrak.