The Inmarsat C decoder currently supports the following features:

• Frequency spectrum display for easy center frequency selection
• Visual indication of carrier, symbol and frame synchronisation
• Ability to display raw or decoded frames
• Disk logging of raw frames, decoded packets, message (non-demo)
• Decode of Message and Polling packets (non-demo)
• Disk logging of broadcasts
• Comprehensive packet filtering
• Realtime packet decode display window
• Waterfall and oscilloscope displays
• Graphical representation of symbol synchronisation
• Ability to vary frame synchronization error threshold
• Bulletin board error calculation
• Automatic Gain Control
• Indication of excessive audio gain
• Support for sound card input selection

This application uses the following open source code:

AE4JY WinPSK1.2 http://www.moetronix.com/ae4jy/oldwinpsk.htm
The Visual C++ 6.0 Project Source Code was used as the basic framework from which the application was written. Many modules provided by Moe were directly useable - waveform display, FFT, Symbol recovery, etc. Carrier recovery, interleaving, scrambling, etc. was all new code that was developed.

Phil Karn’s Viterbi Decoder Library http://www.ka9q.net/code/fec/
The Viterbi decoder was modified for little endian operation but was otherwise used as provided by Phil.

WARNING: Use of this software may not be legal in your country. Consult your local laws before use.

This website has no affiliation with the Inmarsat corporation.