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HFDL extension

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Comments

  • edited November 2021

    John,

    The MUF3000 svg image comes from the prop.kg2c.com website Andrew, KC2G and is generated with a repository found at github https://github.com/arodland/prop .The image is aggregated from the Digsonde network and refreshes every 5 - 10 minutes.

    This is a fairly large repository and it looks that Alex, VE3NEA found a more expedient way of getting this map data for his ft8_mapper script by extracting the pixels from the latest image...

    ft8_mapper runs in a Jupyter notebook and is at https://github.com/VE3NEA/ft8_mapper . It uses cartopy to re-assemble the map and overlaying FT8 data.

    Now if we strip down this notebook for just displaying MUF3000 and use the Mercator projection, the image that the scripts generates looks like the one below. The Jupyter notebook can be converted to a regular Python script, that if run on the kiwisdr.com server could be retrieved by all kiwi nodes.

    Overlay still done manually since I don't know what mapping engine the Kiwi uses for adding layers.

    Alternatively the MUF could be shown separately without trying to overlay the HFDL map or the idea explored later.

    Disregard the MUF contours because they are from a different time than the HFDL map. Colour legend is still missing.

    PS: The ACARS only display works well, thanks.

    73 Ben

  • Based on some observations made whilst using the extension, but not knowing how HFDL actually works........

    I like the map with the active frequencies, I also like the idea of the propagation map.

    I wonder if the HFDL extension could have an option to scan the active ground stations and build up a propagation map based on the reception of those ground stations by the KiWi in use ? Maybe adding coloured propagation lines or paths to match the frequency band a bit like existing WSPR, FT8 psk reporter applications. The advantage of using the HFDL ground stations is that they are better distributed around the globe than amateur stations, run high power and are consistent in operation.

    This information could then be centrally collated and used to produce a contoured map, similar to that described previously.

    I've been following some aircraft which report their position fairly frequently, but they suddenly disappear. I suspect this is because they either change frequency and / or hand over to another ground station. In most cases because of the frequency of reporting, I think it would be possible to scan active HFDL frequencies at a rate of say 5 mins per frequency (approx 2 hours for a full scan, maybe less if LF or HF only selected like the ALE extension), and still have enough data on each flight to be able to track it reasonably effectively.

    Alternatively is there some form of handover between the aircraft and ground station that could be used to follow a specific flight (when flight plotting is available).

    An excellent addition to the KiWi, and I'm still amazed that I've been able to directly track flights as far away as those over central Australia fairly consistently from here in the UK.

    Regards,

    Martin

  • v1.479 November 23, 2021

      HFDL extension improvements:

        Preliminary flight markers added. After 10 minutes without an update the marker is

        considered "old" and color changed to grey. Will change back to blue if a further

        update received. Use "clear old" button to remove grey markers.

         

        Use URL parameter "gs:0" to initially hide the ground station / AFT icons.


  • I have problems decoding HFDL in KiwiSDR. Simply put, it won't decode anything. However, if I pipe the audio to PC-HFDL application, it decodes happily. Any idea on why?

  • >I have problems decoding HFDL in KiwiSDR. Simply put, it won't decode anything. However, if I >pipe the audio to PC-HFDL application, it decodes happily. Any idea on why?

    Your external decoder may be more tolerant to an off-frequency signal or a different receive bandwidth.

    If you select a HFDL band from the drop down list in the HFDL extension, and click on a listed frequency to tune to a ground station that you can see to be active on the waterfall, then you should get some decodes fairly quickly.

    By choosing from the list in the extension, it tunes to the correct frequency and selects the best receive bandwidth for use with the HFDL decoder in the extension.

    When it is working it performs very well, and from the UK I've been able to spot aircraft pretty much all over the world. With the exception of flights over the Pacific, but I think this is due to a combination of factors such as the number of flights, timezones, propagation and frequencies in use at the times I've monitored.

    Regards,

    Martin

  • As noted in the first post of this topic, second paragraph, you may have press the "test" button a few times until you start getting good decodes. And perhaps re-opening the extension if that doesn't work. It is unknown currently why this is needed.

  • @jks

    When I use test feature can decode correctly. But it never decodes any actual HFDL transmission.

    @G8JNJ

    I did start HFDL decoder from the drop down menu and select a frequency. It won't decode anything. The mode of KiwiSDR when selecting the frequency in the extension is IQ mode. When select an HFDL frequency in the bookmark, it goes to USB mode. I don't know if it made any differences. The PC-HFDL decodes best when I set my Kiwisdr to USB mode.

  • The HFDL extension will only work if the mode is set to IQ. It will not work in USB mode.

    If you click on the "DX labels" appearing above the frequency scale that are for HFDL frequencies then IQ mode or USB mode may be selected. If EiBi DX labels (read-only) are being used then IQ mode is always used and you can safely click on the labels. For the default labels (stored, writable) it depends how they've been setup whether IQ mode is used or not. So clicking on them may or may not work.

    So either select EiBi HFDL labels when using the HFDL extension or simply use the frequencies in the two menus of the extension.

  • Ok. for some magically reason, after my previous post, the HFDL start to decode normally. Don't know what's changed. But it works now.

  • Maybe I have too many WSPR Autorun daemon before? The only difference I could tell is I have reduced WSPR Autorun daemon from 4 to 2

  • The flight markers, colour fading and "clear old" are already good.

    In certain areas the screen can fill up quickly with almost overlapping markers and perhaps a radar style marker can be considered, which is less conspicuous. Examples shown below.

    A further addition could be an option to show aircraft tracks based on the earlier position reports that are still retained.



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