Observation 1268573: ITUPSAT 1 (35935)

Satellites & Observations Observations
1

Regarding Observation 1268573 …

@BOCTOK-1 Eleven of these failed due to disk full - I’ve put in a daily cron to clean up any IQ files older than 1 day.

0 0 * * * find /tmp/ -name 1*.raw -ctime +1 -exec rm {} ;

1 Like
2

Why keep raw I/Q data in the first place?

3

To playback later in gqrx and demodulate signals off the center frequency - mainly the cas-4a,b and xw ones have hams off in the linear transponder. Also lately been playing back in gqrx to the apps in gr-satellites to upload telemetry.

4

Not sure what modulations are being used but if you don’t care about the imaginary component of the FFT (Im{FFT}) then you can try saving FFT samples to file (e.g. with GNU Radio) and then running an iFFT (inverse Fast Fourier Transformation) to “restore” the raw I/Q data. Some information will obviously be lost, but it might not matter to you much (depending on the modulation used).

5

Thanks for letting me know! :slight_smile: