ADS-B status

I’ve read some posts from earlier this ear in the archives here, where there was mention of BladeRF’s ADS-B radio. It wasn’t clear to me if there was any compatibility with the LimeSDR. In any case, I am interested in running a receiver for ADS-B that’s more sensitive than the DVB-T dongle hack. What’s the current status of ADS-B for LimeSDR? I am still new to the Lime/GNURadio/Pothos/Soapy ecosystem, so of there os a working suite some installation notes would be greatly appreciated.

The license on the custom made FPGA gateware by Nuand LLC expressly limits the source code and “any derivative works” to be use only on hardware manufactured by Nuand LLC.
i.e. It can only be used on their BladeRF hardware and nothing else.

One option would be to develop a independent clean room implementation written for the LimeSDR, since the ADS-B standard is open. At the end of the day it is just binary bits effectively encoded as an AM signal. It could be implemented by tuning to 1090MHz, selecting the smallest analogue filter in the LMS7002M ( 0.7 MHz), selecting the maximum sample rate possible*, and then pattern match inside the FPGA for a valid preamble ( ref: http://www.radartutorial.eu/13.ssr/sr24.en.html ), have a flag for a valid preamble. In parallel decode the data as Manchester encoded and validate the parity, have a flag for valid parity. If the parity flag is valid, and the preamble flag that coincided with that time was also valid then a ADS-B signal was received, transfer that demodulated string of digits across to the PC.

*maximum because you can decimate within the TSP(Transceiver Signal Processor) and gain extra dB of signal from maths.

A much simpler option might be to install gnuradio and use modes_rx which is part of the gr-air-modes module.

Or to add Lime support to:

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Right, so dump1090 is nice and lightweight, and seems to work well, if all you want to do is receive Mode S.

Stupid question…
Any updates on this topic that you’re aware of?

gr-air-modes should work via gr-osmosdr source block.

If you mean a Lime or SoapySDR fork of dump1090, I’m not aware of one.

Any one using Lime SDR USB for ADS B at the moment ? (not mini)

I have made a hacky version over here: https://github.com/v0l/dump1090_lms

Its a bit messy but it works ok so far ive been using it the past few days

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