Author Archives: trango

Inmarsat Antenna Distribution

Inmarsat L-Band signals from both CONUS and POR need to be routed to various receivers and SDRs, this distribution system is a pretty simple solution (as shown below). It’s based on taking an L-Band signals from a dish, where pre-amplification … Continue reading

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XM-1 S-Band Signal

Need to check dish alignment on S-Band? The 12.5MHz XM-1 signal is a great test signal. XM-1 is a much more interesting signal to look at than Sirius. The signal below is using a 1.8m dish.

Posted in SATCOM Tagged

Chang’e 5-T1 and new 1.8m dish online

New spacecraft and new dish were tested this weekend. The spacecraft is the Chinese Chang’e 5-T1, an experimental unmanned lunar mission that was recently launched by the CNSA. The dish is a 1.8m Prodelin offset and is inverted for ease … Continue reading

Posted in Projects, Spacecraft Tagged

Aero Decoding and Full Support for HackRF One

After some work it is now possible to fully support HackRF One with my Inmarsat Aero decoder. In the past, the Inmarsat Aero decoder used two SDRs (each covering 2MHz) to cover up to 4MHz of L-Band spectrum as well … Continue reading

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Adding External Reference to HackRF One SDR

The HackRF One SDR is a great value but it’s frequency stability leaves something to be desired. Using the Si5338 clock generator from Silicon Laboratories is an easy way to address the problem (if it’s really a problem for your … Continue reading

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HackRF One and Decoders

I’m always looking for opportunities to reduce the costs associated with high quality decoding tasks. The HackRF One is intriguing because it’s not very expensive, has a wide band receiver (10MHz – 6GHz) and an SDR that is capable of … Continue reading

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Aero Coverage of POR and CONUS

The diagram below illustrates the current Aero coverage that is possible here at USA-Satcom. As you can see there is quite a bit of IQ bandwidth to deal with and consequently at least two i7 hex core machines are needed … Continue reading

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Operation Deep Freeze 2014

It’s that time of year again! Regular science crew transportation missions to and from Antarctica using US Air Force aircraft. Communications occur via Military Satcom in the Pacific Ocean Region. Below are a few recent satcom intercepts as well as … Continue reading

Posted in Inmarsat, Milair, SATCOM Tagged

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

Posted in Inmarsat, Projects Tagged

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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