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wav rs41 preamble Aug 3, 2015
rs41.c RS41: multiple aux data Jan 18, 2017
rs41.txt GPS/UTC time Jul 19, 2018
rs41iq.c rs41iq: freq offset sign Jan 30, 2019
rs41ptu.c rs41: rel. hum. v0.2 Apr 9, 2019
rs41sg.c wav_header parameter global Dec 28, 2014

Radiosonde RS41


  • rs41ptu.c, RS/ecc/bch_ecc.c


(copy bch_ecc.c)
gcc rs41ptu.c -lm -o rs41ptu


./rs41ptu [options] <audio.wav>

  • <audio.wav>: FM-demodulated signal, recorded as wav audio file
  • options:
    -i: invert signal/polarity
    -b: alternative demod
    -r: output raw data
    -v, -vx, -vv: additional data/aux/info
    --ecc: Reed-Solomon error correction
    --crc: CRC blocks: 0-OK, 1-NO
    --sat: additional Sat data
    --ptu: temperature

./rs41ptu -h: list more options


FSK-demodulation is kept very simple. If the signal quality is low and (default) zero-crossing-demod is used, a lowpass filter is recommended:

  • sox 20170116_12Z.wav -t wav - lowpass 2800 2>/dev/null | ./rs41ptu --ecc --crc -vx

If timing/sync is not an issue, integrating the bit-samples (option -b) is better for error correction:

  • ./rs41ptu -b --ecc --crc -vx 20170116_12Z.wav

If the signal is inverted (depends on sdr-software and/or audio-card/settings), try option -i.

(cf. /RS/rs92)

older versions

  • rs41sg.c, rs41.c, rs41ecc.c
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