Any tools to save KiwiSDR waterfall to image ?

Hello, I have few questions about KiwiSDR waterfall.
1. What is maximum waterfall bandwidth which we can save ? Can we save all freq range, 30 mHz ?
2. Any tools which can save waterfall to image? Some scripts or programs? For now I found https://github.com/jks-prv/kiwiclient which could saved waterfall to .npy, but I don't know how to convert it to image. Also we can record waterfall with screen capture. But this is not very efficiency way :). Also we can save IQ file to WAV and then draw plot. But in this case only small piece of bandwidth would be showed.

Maybe some other solution exist?

Comments

  • Yes! Right-click on your mouse to bring up the Kiwi utility menu. This is an often overlooked feature. If you have a laptop like a Mac there are different ways to configure the track pad for right-click in addition to the usual left-click (I use the two-finger tap method). One of the menu entries is "save waterfall as JPG". This feature was contributed by Peter, VE3SUN.

    But this is a manual operation. You're probably interested in automatic waterfall recording.

    The kiwiclient waterfall code is currently only for gathering statistics and not saving the waterfall image. But with some code changes it could probably be made to do that.
    kovalr
  • jksjks
    edited September 2020
    To be more precise about the kiwiclient waterfall tools. There are three facilities:
    • The --wf option of kiwirecorder (note not kiwiwfrecorder) prints statistics.
    • Kiwiwfrecorder (note not kiwirecorder) is a specialty program Christoph wrote that saves waterfall data together with GPS timestamps as Python Numpy array format file (.npy) which with some code changes could probably be an image file as well.
    • microkiwi_waterfall.py is a simplified version of kiwirecorder --wf that Marco wrote. A version of which runs his Dynamic SNR Map website http://sibamanna.duckdns.org/sdr_map.html
    kovalr
  • "Kiwiwfrecorder (note not kiwirecorder) is a specialty program Christoph wrote that saves waterfall data together with GPS timestamps as Python Numpy array format file (.npy) which with some code changes could probably be an image file as well."

    I found that Kiwiwfrecorder needs frequency as an option. Does it save all waterfall (30 mHz) or only some passband (10 kHz) which selected in -f option ?
  • It has a --zoom (-z) option which defaults to zero meaning zoomed all the way out (0 - 30MHz). Setting the frequency only matters when you are zoomed further in (values 1-14). These zoom values match the zoom values seen on the Kiwi user interface (i.e. number 'n' after "WFn" tab on main control panel).
    kovalr
  • I see. Ok. Thank you. Maybe someone will write converter from .npy to image. I left github issues. This would be a very cool feature.
  • Note that the zoomed-out waterfall sacrifices the detail to get the bandwidth. There's only so many "bins" that the FFT output fills, and changing zoom level will mean the bins get more fine and more coarse depending on the zoom direction change.

    I.e. you will not be able to get ten Hz divisions across the ~30MHz available, you'll get the (width / number of bins). I'm not sure what the numbers to put in there are but the methodology is sound (afaik)..
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