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Re: R: P3D Report



>I'm looking for write some code to "filter out" signal with "no / almost
>low" doppler, and to recognise carrier doppler affected, marking these that
>fit into the possible range of the spacecraft.
>I suppose that this kind of task is used regulary by some other people
>(NORAD et related Organization) HIHI

This is exactly the algorithm the SETI folks use. They look for
doppler shifts represent the motion of the earth around the sun, and
the motion of the solar system relative to the rest of the galaxy.
This excludes a lot of terrestrial and earth satellite interference,
since they don't have the right doppler shifts.

You do this by pre-chirping the signal by the expected doppler shift,
then doing a FFT on the result using a longer integration time. If the
chirp is correct, then the signal energy will land in a single, narrow
frequency bin.

Phil

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