Input from FM discriminator

We can run AIS-catcher on a RAW audio file as in this tutorial:

wget "https://github.com/freerange/ais-on-sdr/wiki/example-data/helsinki-210-messages.raw"
AIS-catcher  -m 3 -v -s 48K -r cs16 helsinki-210-messages.raw

On this file we should extract roughly 362 AIVDM lines. Notice that with switch -m 3 on the command line AIS-catcher runs a decoding model that assumes the input is the output of an FM discriminator. In this case, the program is similar to the following usage of GNUAIS:

gnuais -l helsinki-210-messages.raw

which produces:

INFO: A: Received correctly: 153 packets, wrong CRC: 49 packets, wrong size: 4 packets
INFO: B: Received correctly: 52 packets, wrong CRC: 65 packets, wrong size: 10 packets