Mike Tests out L-Band STD-C and AERO with a Low Cost Modified GPS Antenna

SDR-Kits.net have begun selling low cost GPS antennas that are modified to receive the Inmarsat satellite frequencies between 1535 MHz to 1550 MHz. They also have a version for Iridium satellites that receives 1610 MHz to 1630 MHz. The antennas are powered by a 3-5V bias tee, so they should work fine with SDRplay, Airspy and RTL-SDR Blog V3 units.

Mike Ladd from SDRplay has recently sent us a guide to receiving AERO and STD-C messages on L-band with the SDR-Kits antenna and an SDRPlay unit running SDRUno (Megaupload link).

AERO messages are a form of satellite ACARS, and typically contain short messages from aircraft. It is also possible to receive AERO audio calls. STD-C aka FleetNET and SafetyNET is a marine service that broadcasts messages that typically contain text information such as search and rescue (SAR) and coast guard messages as well as news, weather and incident reports. Some private messages are also seen. To decode AERO Mike uses JAERO, and for STD-C he uses the Tekmanoid STD-C decoder.

Mike has also created a very handy bank of frequencies for the SDRUno frequency manager which can be downloaded from here.

We note that if you're interested in waiting, at the end of September we will have an L-band patch antenna set available too. Our antenna will work from 1525 up to 1637 MHz. Prototypes have shown have shown good Inmarsat, Iridium and GPS reception. More details coming next month when manufacturing gets closer to finishing up.

Screenshot of the Tekmanoid Decoder from Mikes Tutorial
Screenshot of the Tekmanoid Decoder from Mikes Tutorial
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Like everyone said, i am looking forward to use the new antenna! When can we expect to purchase?

Richard KE7KRF

I started monitoring AERO and STD-C SafetyNet back when Outernet was using L-band. Their air-gap patch antenna and LNA does a fine job of decoding. I have used three different decoders for STD-C — in addition to Tekmanoid (I use the demo version) , TDMA-Demo and Microp11’s freeware Scytale-C. The latter is my favorite and there are two possibilities, a stand-alone version and a SDRSharp plug-in. Any of the above are worth trying and you can then judge for yourselves.

My Outernet patch is indoors and produces sufficient SNR to decode SafetyNet messages as well as 600,1200, and 10500 baud AERO with low error rates. The outernet LNA is powered by bias-T from a higher quality RTL-SDR or can be powered independently.

I look forward to the release of your new patch antenna especially since it will have the expanded frequency range.


I have ordered two of the antennas from SDR kits. Looking forward to getting them and comparing them against my modified GPS antennas that I have been using for the past year or so.
Also looking forward to getting your patch antenna.
We have been using Jareo for ACARS and doing some STD-C decoding as well.
There is a lot of very interesting stuff coming off the Inmarsat, glad to see some new hardware becoming available to tap into it.


Can I buy and beta test your Lband antenna early….I was just about to buy the SDR KITS 2 antennas, but can we work something out I could do a review on back of buying? im in UK….


I’m very much looking forward to your antennas, it opens a whole new bit of SDR that I’ve not had a chance to experiment with. I can’t wait!