dernasherbrezon / r2cloud

Decode satellite signals on Raspberry PI or any other 64-bit CPU.
Apache License 2.0
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Automatically track AAUSAT4 signals #50

Closed dernasherbrezon closed 5 years ago

dernasherbrezon commented 5 years ago

AAUSAT4 signals are deviating from central frequency. In order to decode them, frequencies should be moved left or right based on signal peaks at -1200hz and +1200hz. So the expected decoding process is:

  1. Save 60khz signal
  2. Apply doppler correction and FrequencyXlatingFilter.
  3. Save into temp file
  4. Run FFT over this file and detect peaks.
  5. Find peaks with 2400hz difference +- tolerance. Find deviation from the center frequency
  6. Shift frequency in the temp file based on the found peaks
  7. Run normal decoding over the temp file. I.e. QuadratureDemodulation/ClockRecoveryMM.