A few months ago I started looking at various options for omnidirectional antennas with circular polarization for satellite communications. I came across the TA-1 137 MHz turnstile antenna from Wimo, which looked like an interesting option for a reasonable price.
About a year ago I posted a step-by-step guide about how to receive NOAA APT weather satellite images using Gqrx SDR and the Funcube Dongle. Today, I tried to repeat the procedure using my ezcap eztv666 rtlsdr dongle with very good results.
I have wanted to implement a simple APT decoder for the NOAA weather satellites in GNU Radio for quite some time now, in particular since the USRP equipped with a TVRX or WBX daughterboard and a GNU Radio FM receiver can be an extremely good receiver for this purpose. Today I have spent some time looking at the details of decoding APT and actually ended up with a working prototype implemented using the GNU Radio Companion.
Last weekend I wrote about my spontaneous experiments with receiving and decoding APT transmissions from NOAA polar orbiting weather satellites. This weekend I decided to extend the experiments by trying to receive at very low elevations and get images from far away.
This weekend I ended up receiving APT signals from NOAA polar orbiting weather satellites. I only wanted to explore IQ data recording and playback with GNU Radio but when I first used NOAA 15 as test signal and saw what I could receive I got slightly distracted from my original plan.