Kiwi IQ wav file format

rrobinet

Is there a document which describes the format of an IQ wav file?

If the timestamp is present in the wav file header, what is its resolution and from what clock is it derived? In particular, if the Kiwi is run in external clock mode, does the Kiwi need to also have a GPS RF feed from which the IQ file timestamp will be derived?

When recording a series of IQ wav files using --dt-sec=..., are the IQ samples continuous? i.e. is the first IQ sample of file N+1 one sample time after the last IQ sample for file N?

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I have found the C++ function DEFUN_DLD in read_kiwi_iq_wav.cc, so it appears there is a capability inside kiwi client to parse IQ files. But it isn't clear to me how to execute it

ok1iak

This may be of interest to you

https://github.com/f4exb/sdrangel/tree/master/plugins/samplesource/kiwisdr

Christoph

Hi Rob,

see https://github.com/hcab14/TDoA as an example of how to use the GNSS timestamps.

The timestamps are derived from the GNSS position solution done on the KiwiSDR.

Basically there are extended WAV headers containing the timestamp for every 512 (or 256, don't remember exactly) IQ samples. So such .wav files do not play, e.g., in audacity. Instead you might use the octave function read_kiwi_iq_wav to access the data. Of course the same can be done in python as well.

Hope this helps,

Christoph