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csete / gpredict

Gpredict satellite tracking application
http://gpredict.oz9aec.net/
GNU General Public License v2.0
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Please allow time or angle overshoot for AOS/LOS rigctl signaling in radio control #284

Open yarda opened 2 years ago

yarda commented 2 years ago

I have clear horizon and it seems I have up to 30 seconds of quite a good signal reception before AOS and after LOS is signaled for ISS passes. This adds nearly one minute to the window which could be utilized for nearly half ARISS SSTV PD120 image reception which is worth the effort.

Please add an option allowing time (or maybe angle) overshoot when using AOS/LOS rigctl signaling for automatic recording.

It seems currently 0.0 degree elevation is hardcoded for AOS: https://github.com/csete/gpredict/blob/master/src/gtk-rig-ctrl.c#L2314 and LOS: https://github.com/csete/gpredict/blob/master/src/gtk-rig-ctrl.c#L2331

yarda commented 2 years ago

I patched the 0.0 to -5.0 and it's doing exactly what I needed - i.e. it starts the recording before AOS and stops after LOS. I think the "overshoot" angle or time could be configurable.

yarda commented 2 years ago

It seems -5.0 degrees is quite a lot for me. I tested it in the recent ARISS event and it seemed that with the ISS the -2.0 to -3.0 degrees worked the best for me and there was enough time for the signal to fully fade-in/out on the recordings. I guess it's because the powerful RS0ISS signal bends in the ionosphere. Probably the best options is to have it configurable (in both minus/plus ranges).