[amsat-bb] Re: AO7 in Mode B

Wayne Estes w9ae at charter.net
Mon Jun 17 12:54:20 PDT 2013

K4FEG wrote:

There have been questions as to whether or not a program like SATPC32 is 
calculating the solar position based on ground track or actual satellite 
position in orbit, I have not reached out to find out the method of 
calculations but based on how AO7 has reacted to even the briefest of 
eclipse's as predicted by SATPC32, I suspect the relationship of the 
satellite to the Sun is being predicted based on the actual satellite 
position in orbit and not based on ground track.

W9AE replies:

SatPC32 displays "Sat in Sun" when the satellite's footprint overlaps 
the sun's footprint.  You can see it change to "Eclipse" when the two 
footprints no longer overlap.

In practice, AO-7's solar panel probably quits generating enough power 
when only a portion of the sun's "disc" is obstructed by earth. 
Consequently, the satellite would quit working a bit sooner than the 
actual eclipse, when 100% of the sun is shaded by earth.

This year I plan to make Field Day satellite contacts for the first time 
in several years.  In western Oregon I can operate the un-crowded 
satellite passes where most of the footprint is over the Gulf of Alaska.

Wayne Estes W9AE
Oakland, Oregon, USA, CN83ik

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