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TDoA Successes

List your results here


  • I was able to get within 2 miles of WCBS. CHU results are improving, now within 150 miles
  • From the most precise ones: (i.e. giving a dot, not a curve)

    * Pinpointing several Bulgarian and North Korean embassies in Europe
    * Locating the unid parallel 6-tone MFSK system on 7674, 10222, 12130, 14462, 16115, 17456 in Frankfurt area
  • I found it tough to find 3 stations that could plot WWVB on the map. I don't know if it is because of the type of signal transmitted or what.
    Ron - KA7Uimage

  • @Ron, That image shows IQ mode, but with a center frequency of 59.5 kHz and an unbalanced passband that is much too wide for running TDoA on WWVB. If you actually ran using these settings try running again on exactly 60 kHz with a balanced passband of, say, 100 Hz. Hold down the shift key and then click the +/- magnifying glass icons (zoom icons) to symmetrically adjust the passband. Each time you click the passband is reduced (increased) by 80%. Hover over the left or right yellow passband edge to see the current bandwidth.
  • edited July 2018
    OK, that did a much nicer result. Very nice! I did check the results and found the triangulation point to be approximately 70 miles north of the transmitter towers. I suppose KiwiSDR location information could be inaccurate and other reception anomalies could affect the accuracy as well. Still 70 miles is pretty close.
    Ron - KA7U

  • Good fix on the BBC Radio 4 transmitter near Droitwich, just south of Birmingham.

    When zoomed in the site was within the centre circle.

  • Hi,
    China Radio International Kashi-Saibagh (Coordinates: 39°21'40"N 75°44'43"E).

    Dirk SWLJO43
  • Super,

    13760 kHz, Kujang (200 kW)
  • I'm quite pleased with this one, especially as it's an HF signal and there are not that many suitably placed KiWi's.

    It's a Russian CIS-12 signal on 11175KHz.


    Martin - G8JNJ
  • I experimented with the 180 degree path crossing. It fails everytime. I can hear the station with my receiver, but it won't plot with the other receivers for this station. Still good results with stations not crossing the 180 degree longitude, I'd say.
    Ron - KA7U

  • Congrats. That's the first DF of NWC I've seen. I've tried from here but the NZ Kiwis capable of hearing VLF are either off or can't get it anymore (i.e. mine).

    There are problems when stations cross 180 deg even when the map range doesn't. I haven't had time to look into it in detail yet.
  • jksjks
    edited July 2018
    If anyone takes the time to find the actual antenna field on a satellite map send me the coordinates and I'll add it to the list of reference stations. Often the facilities are already identified on Wikimapia, e.g.
  • DHJ59 (Wilhelmshaven GER)

    53.677, 7.612
  • Chayka transmitter Simferopol, RSDN-3 44.88895, 33.87334

    Chayka transmitter Slonim, 2nd station of RSDN-3 53.132, 25.396111
  • Martin, could add which RX you used on those?
  • I haven't TDoAed the two VLF sites, but I thought it was worth adding them to the map prior to trying.

    Wilhelmshaven is the result of a TDoA of a STANAG transmission on 12176KHz USB. Unfortunately I didn't save the setup.


    Martin - G8JNJ
  • edited July 2018
    FSK with 500Hz shift 12183KHz USB

    Istra near Moscow 55°53'03.0"N 36°57'13.0"E

    More Russian sites listed here.
  • edited July 2018
    I'm pretty impressed with this one which is easily within 10Km

    STANAG on 12668KHz using,lat:43.36,lon:2.17,z:9,map:1,DF0KL,CS5SEL,G8JNJ,LA3SP,SA0CAM,SV8RV,FUG


    Martin - G8JNJ
  • HFDL transmitter sites - very often shared with other aero comms

    Longitude 121 45 34 W Latitude 38 22 48 N

    Ground Station ID 2 MOLOKAI - HAWAII
    Longitude 157 10 46 W Latitude 21 10 47 N

    Ground Station ID 3 REYKJAVIK - ICELAND
    Longitude 21 50 59 W Latitude 64 4 47 N

    Ground Station ID 4 RIVERHEAD - NEW YORK
    Longitude 72 38 22 W Latitude 40 52 47 N

    Ground Station ID 5 AUCKLAND - NEW ZEALAND
    Longitude 174 48 35 E Latitude 37 1 10 S

    Ground Station ID 6 HAT YAI - THAILAND
    Longitude 100 23 24 E Latitude 6 56 23 N

    Ground Station ID 7 SHANNON - IRELAND
    Longitude 8 55 46 W Latitude 52 43 48 N

    Longitude 28 12 35 E Latitude 26 7 46 S

    Ground Station ID 9 BARROW - ALASKA
    Longitude 156 46 46 W Latitude 71 18 0 N

    Ground Station ID 11 ALBROOK - PANAMA CITY
    Longitude 79 32 59 W Latitude 8 58 12 N

    Ground Station ID 13 SANTA CRUZ - BOLIVIA
    Longitude 63 7 46 W Latitude 17 40 11 S

    Ground Station ID 14 KRASNOYARSK - RUSSIA
    Longitude 92 18 0 E Latitude 56 6 0 N

    Ground Station ID 15 AL MUHARRAQ - BAHRAIN
    Longitude 50 39 0 E Latitude 26 16 12 N

    Ground Station ID 16 AGANA - GUAM
    Longitude 144 48 0 E Latitude 13 28 11 N

    Ground Station ID 17 CANARIAS - SPAIN
    Longitude 15 23 23 W Latitude 27 56 59 N
  • Aarhus - Danish navy

    56.1228, 10.2068
  • JORN OTH radar from Australia - performed by linkz:
  • Russian Embassy, Paris - only 10 km away from the actual location
  • PBB, Dutch Navy, Den Helder

    52.9192, 4.7436,lat:52.18,lon:4.21,z:6,G8JNJ,G0LUJ,F1JEK,DF0KL,DC9FD

    PBC also annotated on results map.


    Martin - G8JNJ
  • DJH58 German Navy, Hurup, Near Glücksburg/Saterland-Ramsloh, Germany 54.7606, 9.5499

    DHO26 German Navy, Near Rostock / Marlow, Germany 54.1438,12.5504

  • edited July 2018
    DHJ59, German Navy, Wilhelmshaven, Germany 53.677, 7.6120

    Note - Not operating on LF 53KHz for site reference only
  • Fantstisch, thanks to John and TDoA-Scripter and the good KiwiSDR's that I can use. Dirk (SWLJO43)
  • VLF Transmitters at Cutler, Maine, call sign NAA. 44.645,-67.283 covering the peninsula.
    Ron - KA7U
  • Radio Marti in Greenville NC was an easy find on 6030, a good reference station
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