Below is graphical overview of Marine-C, an Ethernet based Multi-Channel Inmarsat-C decoder. The decoder is able to simultaneous decode up to 12 channels and therefore can cover an entire ocean region with this single application. The decoder monitors all LES channels as well as the main NCS channel and properly decodes all messages and bulletins, including data and text. All results are automatically saved and can be left un-attended without missing anything. Two SDRs are required because the NCS and LES channels are too far apart to capture with single SDR.
Below shows some sample output for message status, LCN and SDR status. Also shown is FFT of NCS and various LES channels. You don’t need to run the IQ viewers for normal operation.
The output is directories with text and data files as shown below.
Since this application is entirely Ethernet based you may be wondering how I am using the SDR-IQ, which is USB based.
The SDR-IQ is hosted on a Raspberry PI and serves up the appropriate Ethernet packets so that the main decoder application just sees another SDR-IP or NetSDR.