Yes, AO-27 used a similar technique ("TEPR") beginning not long after launch and for similar reasons - a computationally easy (for the satellite) way to control the transmitter (time after exiting eclipse) to ensure a positive power budget. Although the link to the original page on amsat.org explaining it is broken, a copy was posted here: http://www.om3ktr.sk/druzice/teprstates.html The diagram assumes the satellite orbit is counter-clockwise and the "on" times are for descending node (North to South) passes. Re-order the segments for ascending node (South the North). The AO-27 command team later replaced "TEPR" with "TOPR", using an algorithm based on when the satellite is over the desired latitude band - easier for humans to understand, more calculating on the satellite. (Guessing this occurred in late 1996-early 1997 based on amsat-bb email archives)
The EO-79 control ops will have to adjust the timer settings in the satellite's software periodically to keep the transponder's "on" time roughly over the same latitude range. Otherwise, as was experienced with AO-27, the band of latitudes where the transponder is on will "drift" seasonally. It will move South approaching the Northern hemisphere winter solstice next month, and move North until the summer solstice.
73 Steve KS1G
-----Original Message----- From: Greg D [mailto:[email protected]] Sent: Saturday, November 12, 2016 2:41 PM To: Amsat BB Subject: Re: [amsat-bb] Tracking EO 79
Didn't AO-27 do something very similar? There was an application for it that did the calculations. I forget who the author was; perhaps it (the program, not the author) could be modified for EO-79?
Greg KO6TH
Paul Stoetzer wrote:
It's basically calibrated for mid-northern latitudes now, so we should hear it on daytime NA passes.
It wouldn't be difficult to write a script to calculate on and off
times.
73,
Paul, XE3/N8HM (currently in Progreso, Yucatán, Mexico)