Thanks to Dave for submitting news of his recent release of his Python script called dopplerscript. This is a tool that can help people automate the reception and decoding of the Meteor M2 weather satellite in Linux with GNU Radio by providing a tool for automatic Doppler correction. He writes:
gr-gpredict-doppler is an out-of-tree gnuradio block for getting doppler updates from gpredict into a flowgraph. I’ve written a small python script (based on pyephem) that replaces gpredict for generating the doppler updates. This script allows one to automate scripting the reception of Meteor M2 satellite transmissions while compensating for the doppler shift.
dopplerscript is a command-line tool to input satellite doppler shifts into a gnuradio flowgraph. The doppler.py script replaces gpredict as the source for doppler frequency updates in gr-gpredict-doppler, making it easy to script satellite reception.
As low earth orbit satellites fly very quickly overhead, the signal will be affected by the doppler effect, thus shifting the frequency as it moves towards and away from you. Tools like this can be used to predict and compensate for this effect and thus providing better signal processing. Meteor M2 is a Russian weather satellite in low earth orbit which transmits digital LRPT weather satellite images that can be received with an RTL-SDR or other SDR.