Coastal HF RADAR Program

Discussion in 'Amateur Radio News' started by KA0KA, Feb 21, 2019.

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  1. WA4ILH

    WA4ILH Subscriber QRZ Page

    I notice that they stay clear of the HF Aeronautical bands as well.
    Tom WA4ILH
    KQ6XA likes this.
  2. KJ7WT

    KJ7WT Subscriber QRZ Page

    This is quite amazing. I have seen signals like these quite frequently, and assumed they were some kind of local interference (switching supply, or something similar). Finding out that they are actually HF radar signals is really concerning, as past history (like the Russian "woodpecker") shows that governments have no problem running roughshod over amateur radio operation. Also, I expect that there is really nothing we can do about it.
    KQ6XA likes this.
  3. W4KJG

    W4KJG Subscriber QRZ Page

    Thank you for starting this thread. I've seen these signals just above 75 meters since I got my first RTL-SDR dongle, and wondered what they were.

    KQ6XA likes this.
  4. KQ6XA

    KQ6XA Ham Member QRZ Page

    Here is a good example of an HF Radar that was transmitting on several frequencies in the 20 meter ham band today at about 2330 UTC.
    It transmitted at about 50 second intervals, with a few seconds duration of signal.
    10 kHz bandwidth.
    14282 kHz
    14305 kHz
    14201 kHz
    And other frequencies.
    It transmitted several times on each frequency, then moved to the next.

    It is probably not a scientific CODAR or Seasonde oceanic research radar :rolleyes:

    The appearance on the waterfall is affected by the scan rate and total bandwidth of the waterfall receiver.
    It usually appears sawtooth-like when viewed at the widest span of the spectrum.




    N0TZU likes this.
  5. KA0KA

    KA0KA Ham Member QRZ Page

    Bonnie: It sounds like you are very interested like I am on these signals, I think below may describe your findings, both are very frequency agile, the JORN 'sample' is mono-stable but typically bounces around just like the AN/TPS-71 does. In the videos, there are specific notes on what you can look for to ID each. Mainly, AN/TPS-71 ops in 8 and 16kHz 'most' of the time, but I have seen it at 50/100kHz with short bursts. JORN at times has about a 10kHz FMCW sweep. There are several other programs as well, with the help of N1SZ and K3DCW I was able to put and ID to and will be posting to youtube, I could re-post these on QRZ in a few weeks as well as only a few people scroll though the comment sections and may have questions like you and me. Enjoy-

    KQ6XA likes this.
  6. KQ6XA

    KQ6XA Ham Member QRZ Page

    Hi Tyler,

    Yes, the HF radars around the Pacific are quite strong here on the west coast of California.
    When I was in Hong Kong, we heard a 50kHz and 100kHz bandwidth radar that visited 40 metres for hours on end... sometimes S9+60dB... and we all knew where it was coming from.

    The 2o metre example I posted earlier probably wasn't JORN... it didn't have JORN's characteristic centre-of-sweep unmodulated CW that immediately precedes the usual JORN sweep.

    Your videos and commentary on the radars are quite informative.
    Please keep up the good work.

    A lot of the west coast CODAR / Seasondes that were in and near the 5 MHz ham band have moved down to 4 MHz recently.
    There were a couple of CODARs on Oahu that covered the 27MHz CB band near Honolulu.
    KA0KA likes this.
  7. KQ6XA

    KQ6XA Ham Member QRZ Page

    Here is a one minute waterfall HF spectrum snapshot of a few minutes ago, Saturday morning here in California.
    Some of the signals annotated: coastal ocean radars (CODAR) and HF radars (RADAR) and IONOSONDEs.

    N0TZU and KA0KA like this.
  8. K6CLS

    K6CLS Ham Member QRZ Page

    Is the ARRL Spectrum Defense aware of these I wonder what they would say?
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  9. KQ6XA

    KQ6XA Ham Member QRZ Page


    There is an ancient saying:
    "Does the fire dragon fear the origami tiger?"

    Last edited: Feb 23, 2019
    WZ4K, N0TZU and W0PV like this.
  10. K6CLS

    K6CLS Ham Member QRZ Page

    And then there's Puff the magic dragon, and Little Jackie Paper. The song makes me cry every time.

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