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Possible TDoA problem when using KiWi's in 3 CH mode [fixed in v1.255]

edited January 2019 in TDoA topics
This afternoon I tried using my second KiWi (in 3ch mode) running v1.250 to perform some TDoA runs.

The initial sampling completed OK, but when it tried to process the captures, after a while it came back with an "out of memory: use fewer Kiwis or check signal quality" error message.

Selecting the same TDoA but using my public KiWi running v1.249 in 4ch mode ran OK.

Changing my second KiWi running v1.250 back to 4ch mode and the TDoA ran OK.

Changing my second KiWi running v1.250 back to 3ch mode and I get the same error message.

I have previously used the KiWi in 8ch mode for TDoA and this ran OK, so I assume it's just a problem with the 3ch Mode.


Martin - G8JNJ


  • TDoA assumes that all IQ wav files were recorded with the same sampling rate, and some of the quality checks on the IQ data are tuned to 12 kHz sampling rate. If you combine recordings with different sampling rates it will not work as it is now.
  • 20 kHz Kiwis should now be removed from the list of TDoA eligible Kiwis.
  • I set mine to zero available for TDoA
  • edited January 2019
    I've noticed that a number of kiwis I've been using for TDoA all the time started throwing up errors, and turns out that's because they went 3 channel. Shame to see them go.
  • I will be opening up channels on my wspr boxes at some point soon..
  • Christoph has identified the issues necessary to make 20 kHz Kiwis work with TDoA (in principle at least). One issue was implemented in v1.252/253. Others to follow as time permits.
  • edited January 2019
    I opened another kiwi here without 20 KHz to get my TDoA back online..
  • Today's v1.255 release allows a mix of 20 and 12 kHz Kiwis to be used for TDoA. 20 kHz Kiwis have been added back to the TDoA-eligible list. Until the majority of Kiwis have updated to v1.255 make sure you're running the TDoA extension on a Kiwi running v1.255 if you're using a 20 kHz Kiwi in your list of sampling stations (the 20 kHz Kiwi itself doesn't have to be running v1.255).

    From the CHANGE_LOG file:
    v1.255  January 7, 2019
        TDoA improvements:
            20 and 12 kHz Kiwis can now be used together in computing TDoA solutions.
            Old TDoA algorithm is deprecated and no longer available from user interface.
            New "spiderfy" user interface for marker clusters:
                When the mouse moves over a marker cluster (circle with number representing the number
                of contained host or reference markers) a popup list used to be displayed.
                But this popup list was static and you couldn't selected an entry by clicking on it.
                Now a "spiderfied" view of the cluster is presented where the contents of the cluster
                pop-out and are linked back to the center of the cluster with white lines.
                While popped-out you can click on the host or reference marker to select it.
                To remove the spider mouse over another cluster or click on the map (outside a cluster).
                To revert to the old user interface start the TDoA extension from the URL specifying
                the "prev_ui:" parameter e.g. "mykiwi:8073/?ext=tdoa,prev_ui:" (note ending ":")
                There is still a problem of markers sometimes overlapping each other when selected as
                sampling stations or as the reference station.
  • v1.256 is out which fixes a bug I introduced in v1.255 which caused many TDoA attempts to fail completely.
    Also some further UI improvements:
    v1.256  January 8, 2019
            Fixed bug introduced in v1.255 causing some TDoA solutions to fail.
            UI improvements:
                Mousing over markers makes them highlight in yellow.
                Marker overlap. When markers (Kiwis and reference stations) are located within 2 km
                of each other the selected marker(s) are separated by a small amount. This amount
                matters less in terms of location accuracy as the zoom level is increased.
                So it's a compromise between less overlap and marker accuracy.
  • v1.258 is out with TDoA UI and reliability improvements:
    v1.257, 258  January 9, 2019
        TDoA UI improvements:
            Added "4" button to zoom buttons at upper left. Zooms directly to level 4.
            Shift-clicking on the +/- buttons zooms by 3 levels instead of just one.
            Added distance scale (in km/m & miles/feet) to map at lower right.
            Added ruler function. Click on the "protractor" icon at lower right. Mouse cursor will
                change to cross symbol. Click on starting map position. Move mouse to ending map
                position and double-click to end ruler measurement. Or single-click to make
                intermediate measurement and continue. Click on icon to clear measurement.
                Don't use escape key as that will close the extension! (this may be fixed in the future)
        Admin GPS tab: now says "loading maps..." when display delayed due to map download process.
        By request: URL parameter "no_geo" to disable browser from determining and sending Kiwi the
            geolocation information of the connecting user.
            Use like other URL parameters, e.g. "mykiwi:8073/?f=5Mam&mute&no_geo"
            This will someday become one of the "user preferences" options.
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