Hi Antoine,

I have tried to modify the AIS decoding implementation from Nick Foster (https://cgran.org/wiki/AIS) in order to be able to use an rtl dongle as a source. Unfortunately I am not living by the sea and I cannot test it before a couple of week. Is there anybody able to receive AIS messages willing to test my changes? You can find it on github: https://github.com/asirinelli/gr-ais

If someone provides a standard gnuradio-format cfile of AIS you can run it offline using a device argument of the form --args "file=/path/to/your.cfile,rate=2048e3,repeat=true,throttle=true" in the osmosdr block. Note the mandatory rate argument and optional repeat & throttle arguments.

The 2 main assumptions I made are:

• Nick first implementation is working

Never had a chance to test it myself.

• rtl-sdr is able to have a sample rate of 256 kHz.

Unfortunately this is not the case. You still could use a higher sample rate here (1024e3 or 2048e3) and then apply decimation/resampling until you reach your required samplerate.

Best regards,

Dimitri