Regarding Observation 5625773 …
This observation may have the first captured beacon from OreSat0. I would love to look at the raw capture and attempt manual decoding to verify. Are captures available somewhere?
Sorry for the newb question, I’m still getting oriented around here.
Thanks!
Indeed this is the first beacons of ORESAT0 received by SatNOGS. Due to the preliminary TLE set that was used and the rest rf environment there wasn’t any demodulation of the signal. You can try demodulate it using the audio (you can download it from the observation page), but have in mind that audio is a compressed file, the raw IQ data aren’t saved currently due to their size (with some exceptions but not our case here).
Thanks for the quick reply, @fredy! I’m not seeing nearly enough resolution in inspectrum or baudline after processing with sox to demodulate FSK 9600. Is that something you have seen work before? Surely it would be possible on other observations containing CW, but this is only FSK 9600.
Yes it have worked several times, in some cases we had decoded data from audio that weren’t even visible in waterfall. But the frequency band of the audio is narrower and also there is compression so maybe the signal is not full or the audio compression in combination with the snr doesn’t help in this case.
EDIT:
Here is a sample command we have used in the past:
sox -t ogg ./satnogs_5294157_2022-01-15T05-04-06.ogg -esigned-integer -b 16 -r 48000 -t raw - | direwolf -B 9600 -b 16 -n 1 -r 48000 -q hd -t 0 -q h -q d -d p -d t -a 0 -
Thanks for the excellent example! I now have a collection of 124 unique beacons with good crc32 values. And thanks to the fine API, scanning through all of the OreSat0 observations was reasonably painless.
@fredy Thanks for this! I can now say one of my ground stations finally produced an observation with a valid decoded frame using this post-processing sox/direwolf method.