Updated March 2021
Weather Satellites transmit High Resolution Pictures (HRPT) at 1.7 GHz. The transmission is not encrypted and all needed is a low noise antenna and LNA , an SDR and suitable software for demodulation, decoding and visualization.
The minimal, portable setup regularly in use here is an Airspy Mini USB SDR , a 40cm diameter helicone on a tripod tracking sats by hand, a 0.2 dB NF LNA.
Details below:
SDR :
SDR Airspy Mini and USRP1 (modified clock 48 MHz, streaming 6 MSPS)
Antenna and Tracking :
a) Hand tracking using a small low noise helicone antenna (see dimensions below)
b) Automated tracking either with USA_SATCOM’s UltraTrack software or my own EME FUN software and the EME FUN antenna controller
Low Noise Amplifier:
Modified G4DDK VLNA NF 0.2dB – important when the low noise helicone is used.
For demodulation and decoding one could use one of the following:
c) Aang254’s excellent free demodulators and decoders for L, S, X band weather satellite : https://github.com/altillimity !!!
For visualization / false color images :
a) David Taylor’s HRPT reader and
b) Fred Jansen’s weathersat
Some pictures showing this small portable setup and what it can do , can be found below.
1.7 GHz helicone design:
The helicone antenna below has been simulated and optimized in CST Microwave Studio.
The goal was minimum dimensions for acceptable G/T performance.
Very good article. I see that the USRP is using sample rate of 2 MSPS. Would that be means RTL SDR also can be used?
Hello, thanks for reading. I haven’t played with the RTL SDR. It may work with some modifications of course. If you give it a try, please share your results. Regards, Michael