Using doppler on GQRX raw files

[RYNEQ]

I'm trying to use doppler on GQRX's raw files like this:

cat gqrx_20220804_154702_137100000_80000_fc.raw | doppler track --frequency 137100000 -i f32 -o f32 -s 80000 --time 2022-08-04T15:47:02 --tlefile weather-tle.txt --tlename 'NOAA 19' --location lat=x,lon=x,alt=x > fixed.raw

But resulting file is neither playable in GQRX nor SDR++

I tried to convert resulting file to i16 format using sox:

sox -t raw -e floating-point -b 32 -c 2 -r 80000 fixed.wav -t raw -e signed-integer -b 16 -c 2 -r 80000 fixed_i16.raw

and i got:

sox WARN dither: dither clipped 34814543 samples; decrease volume?
sox WARN sox: `dop.wav' input clipped 39521951 samples

while before the doppler shift there was no problem with this command

As I know GQRX records raw file in little endian float 32 bit, 2 channel IQ file (one for I and one for Q)

What is the problem?

[andresv]

Haven't used it quite some time. However could you share your gqrx_20220804_154702_137100000_80000_fc.raw maybe I have a chance to look into it.

[RYNEQ]

Haven't used it quite some time. However could you share your gqrx_20220804_154702_137100000_80000_fc.raw maybe I have a chance to look into it.

Thank you, Here is the gqrx_20220804_154702_137100000_80000_fc.raw: https://mega.nz/file/E2BjBICR#QTBmv8v_jh7lXGBEb4FaRhU8rdW--iJi12RJ_PJWC_M

I also tried to apply a zero const shift to it and again got the same result.

I tried to investigate output and it seems there is some overflow and clipping I recorded another signal (137.1 MHz with sample rate 144000) file and I applied a const 50Hz shift like this:

cat gqrx_20220806_143821_137100000_144000_fc.raw |doppler const -i f32 -o f32 -s 144000 --shift 50 > gqrx_20220806_143821_137100000_144000_fc_f32_shifted50.raw

Then I tried to compare time and frequency domain of original and result file, and I see lots of clippings:

Spectrum:

Time Domain:

[andresv]

Oh my, something must be horribly wrong. It spiked my interest. I try to allocate time for investigating. Thanks for clear example.