Tag Archives: L-Band

AERO-I 600 Baud GMSK

Currently there are 9 AERO-I 600 Baud GMSK channels on POR. Quite a bit of ACARS and CPDLC traffic along with the usual Call Management signaling units. These signals are huge as you can see from the “tightness” of the … Continue reading

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Aero Crypto Calls

Finally found an Aero H/H+ call that was encrypted. Supported crypto services on Aero are US-STU-III (Secure Telephone Unit), STE (Secure Terminal Equipment), FNBDT (Future Narrow Band Digital Terminal). Not clear which service this actually is but I suspect it’s … Continue reading

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Fleet Tracking on Inmarsat 4F3

Most of the popular Inmarsat activity is associated with ships and planes in AOR-E, AOR-W, POR and IOR. There is an Inmarsat satellite called 4F3 parked at 98W that gives CONUS coverage. This satellite is inclined and so does move … Continue reading

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New Inmarsat Aero-H and H+ Decoder in Development

Another new decoder project is in the works. This is another Multi-Channel decoder for Aero but instead of just ACARS and CPDLC it does AMBE and LPC voice decode. The screenshot below shows call logging status output from the prototype … Continue reading

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Inmarsat Aero-P ACARS Multi-Channel Decoder

Inmarsat Aero-P includes an ACARS service for airlines to use while transiting the various ocean regions. This is much more reliable than HF ACARS. Inmarsat hosts 3-4 Aero-P control channels on L-Band for each ocean region. Each control channel is … Continue reading

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Multi-Channel Inmarsat-C Decoder

Below is graphical overview of Marine-C, an Ethernet based Multi-Channel Inmarsat-B 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 … Continue reading

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Multi-Channel Inmarsat-B Decoder

Below is a graphical overview of Marine-B, an Ethernet based Multi-Channel Inmarsat-B decoder. Below is a more detailed block diagram of multi-channel decoder with a few screenshots of operational logging and FFT waveforms. Marine-B is a fully automatic frequency agile … Continue reading

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Inmarsat B Decoder

This is a multi-channel Inmarsat B Decoder. It uses a single RF-Space SDR-IP to receive L-Band IQ data via Ethernet and then does all demodulation and decoding in software. The demo below has 5 voice decoders, although only 2 are … Continue reading

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NOAA HRPT Weather Satellites

There are some nice wide HRPT signals coming from NOAA 15, 18 and 19 (others too, but these are the ones I looked at today). NOAA 15, 18 and 19 are LEO satellites and therefore require real time tracking. Since … Continue reading

Posted in SATCOM Tagged

Inmarsat STD-C

Inmarsat STD-C is a data or message-based system used mostly by maritime operators. An Inmarsat C terminal transmits and received on L-Band to various geosynchronous satellites that service each major ocean region (POR, IOR, AOR-E, AOR-W). The information rate is … Continue reading

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