[amsat-bb] AO7 mode switch

K4FEG K4FEG at k4feg.com
Wed Jul 31 09:31:38 PDT 2013

Hello Satellite People;

it is my opinion that we are quickly approaching the end of the Eclipse 
Cycle for AO7 this season. I had previously estimated the "final" 
eclipse to be on August the 2nd between 0200 and 0300 UTC but upon 
closer check with fresh Kep's  it looks like the eclipse durations are 
decreasing by approximately 10 seconds per orbit at this time and with 
the current durations of the orbits the final eclipse of 20 seconds will 
end at 21:00:50UTC, when the satellite is rising over Australia.

I would guess that at that point the 24 hour mode switch will begin once 
the satellite is in full illumination once again. It appears to have 
been 9 full weeks of eclipse's for AO7 and over 98% of the time it 
seemed to come up in Mode B, I know there were reports over Europe of a 
Mode A pass on individual orbits and I had noted the same for the USA as 
well, but once the satellite had gone into eclipse on the next orbital 
pass it would come back up in Mode B.

In May of 2014 I hope to look at the beginning of the Eclipse Cycle and 
work at predicting the beginning and end of it better.

This has been a fun exercise for me and I appreciate those from around 
the world that forwarded their observations to me.

Now it is time to sit and wait to see if the switches start back on 
August 2, 2013 at @21:00UTC


More information about the AMSAT-BB mailing list