On 02/02/2019 00:16, Steven Franke via wsjt-devel wrote:
Aside from the waterfall display itself, the numbers that are used to create it are not available for processing by external programs. The Fourier transforms that are displayed in color-coded form on the waterfall display are calculated in the Fortran routine src/lib/hspec.f90. This routine is called from the C++ code in src/widgets/mainwindow.cpp. You’ll be able to find the point where hspec is called by searching for the word “hspec” in the mainwindow.cpp file.

Hi Joe,

further to Steve's points, maybe you have not realized that the waterfall and 2D spectrum display in WSJT-X are not part of the decoding process, they are simply a visualization of the received signal in the frequency domain using just amplitude information from DFT processing of short chunks of time domain PCM samples as they arrive from the ADC. The whole Rx period of samples are collected and passed to the decoding routines at the end of the period where they are sliced and diced in frequency bins specifically appropriate to the mode being decoded to find candidate signals and signal extraction of those candidates. This decoding processing does not use the frequency domain data accumulated for display on the waterfall and 2D spectrum.

Also a small correction to Steve's points above, lib/hspec.f90 is used for the horizontal fast mode waterfall analysis. For the slow modes the vertical waterfall and 2D spectrum plot are derived by the lib/symspec.f90 routine which does the required DFT transformations.

73
Bill
G4WJS.



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