How a leftover from the cold war turned into a weather and climate tool

This trapezoid shaped clearing in Modoc county, CA, has an interesting purpose. See image below:

File:OTH-B coverage.gif

I visited this years ago, but didn’t learn until today that NOAA started using it for “climate research”. Even “Tropical storms and hurricanes were tracked, and a system for delivering radar-derived winds to the National Hurricane Center was developed.”

Here’s a wind vector image from it:

Apparently it has now been decommissioned and disassembled.

Full story here.

The scientific paper about its use in weather and climate research from BAMS, here

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24 thoughts on “How a leftover from the cold war turned into a weather and climate tool

  1. If it can be used for another good reason, considering the money spent, it would be a good idea. I don’t suppose wind power would be good enough for this 1Gw monster

  2. So wait a minute. If it was so useful to NOAA, why did it get decommissioned?
    ===========

  3. The Navy maintains a similar system looking south (as far as I know it’s still in operation). It’s used mostly for drug traffic interdiction, and is of limited utility because drugs don’t go by airplane much any more.
    What the military is most interested in is rocket launches, and they have satellites for that. An unclassified variant of that system is used by GOES as a fire detector.
    Extremely long-range radar has such coarse resolution, given a practical antenna aperture, that it really isn’t of much use for military purposes.

  4. Hey, we have them, too! We call it Jindalee Operational Radar Network. It cost an arm and a leg to build, almost cancelled at one stage. Even in mid-90s it could detect aircraft taking off and landing in Singapore airport thousands of Ks away. It works by bouncing off radar signal between ionosphere and the surface several times until it hits a target and bounces back again, hence ‘over the horizon’.
    It comes in different sizes and shapes.
    http://maps.google.com/maps?ll=-22.967561,134.447937&spn=0.025,0.025&t=h&q=-22.967561,134.447937
    http://maps.google.com/maps?ll=-24.291095,143.195286&spn=0.025,0.025&t=m&q=-24.291095,143.195286
    http://maps.google.com/maps?ll=-23.658047,144.145432&spn=0.025,0.025&t=h&q=-23.658047,144.145432
    What shape is this?
    http://maps.google.com/maps?ll=-28.317378,122.843456&spn=0.025,0.025&t=h&q=-28.317378,122.843456
    Quit the conspiracy theories already. This is not a landing strip for alien spaceships.
    http://maps.google.com/maps?ll=-28.326747,122.005234&spn=0.025,0.025&t=h&q=-28.326747,122.005234
    As to whether these expensive insruments are currently used for climate research, I dunno. But it sounds like a good idea, 99.

  5. I thought this was going to be another story about the early warning radar sites in the arctic. The technicians were told to take temperature readings, but rather than freeze their tails off and risk becoming dinner for a wolf or polar bear, they’d just write in a number that seemed reasonable. Didn’t seem to matter if they wrote -52 or -47. The logs are now being used as temperature data.

  6. Interesting! I used to hear those things on SW all the time but hadn’t thought about them lately.
    Here’s a technical article written by hams, giving more detail about why the radars were turned off, and an understandable explanation of the ocean-wave use:
    http://ecjones.org/backscatter.html

  7. There was a similar one developed in central Australia, starting with a familiar Australian name “Geebung” and later developed into “Jindalee”. Lots of teething problems, if the reporting was accurate. I think it was a world first for the large “over the horizon” types of Radar.

  8. kim: Too expensive to operate and maintain. The Air Force didn’t care to keep it because it wasn’t looking at anything interesting to them — it didn’t cover potential launch sites for missiles, and bombers are a minor threat nowadays. It would be too much of a chunk out of NOAA’s budget, and the AF would want to control it anyway, because whoever was operating it would know a lot more about US military operations than was really desirable (to the military). There’s also what might be called the “LeMay Effect” — both the military and science are subject to fads and fashions, and all the Kool Kids are doing satellites.
    The Australian system is useful because it covers the most likely launch points in China, although it’s “official” capability doesn’t show that. The Navy’s south-looking system stays because of the reflex “drug war? cool, here’s some money.”
    The technology lives on in all kinds of nooks and corners. Doppler radar for cloud movements, tornado detection and suchlike, is a derivative of the same tech that OTH-B needs (though not a descendant), and there are rumors of “binary” radar being employed. Next time you’re out West you might also take note of all the radome bubbles scattered along the Continental Divide, as well.

  9. Polistra: Excellent article there!
    I favour the refraction theory myself. It makes so much sense. I attended a lecture on the subject about 30 years ago given by a Toronto HAM who demonstrated a pretty convincing beam azimuth change idea. Injecting the signal into the F2 layer was, at certain angles, able to give what appeared to be a refracted signal that skipped the skips, so to speak, at all ground stations between the transmitter and a distant receiver.
    It could be argued that the signal was bouncing within the F2 (internal reflection) several times, then emerging after reacing either a critical F2 stability point or a certain angle.
    Only the remote station received the transmission, and the total signal power at the far end was much higher than that possible with a ‘multiple bounce’ signal which was a big part of his argument: conserved power indicates a ‘channeled signal’. HF wavepipe.
    It seems reasonable that the moving ionispheric plasma could produce both the Doppler shift and the refraction/internal reflection necessary to deliver a large measure of the initial power at a ‘refracted’ frequency (i.e. shifted).
    And yes I remember those stupid OTH radar woodpeckers bouncing my meter. Right up there in Tesla power territory. One day a frustrated US station swung his beam, turned on his afterburner and yelled, “Shut that damn thing off!” And they did.
    /3DA0AC (in those days 3D6AC)

  10. Back in the day I did some DEW Line time . . there were a couple of these back scatters up there, can’t recall the sites, but FOX & CAM Main come to mind.
    They were strictly off limits to peons working the Line.

  11. Australia further perfected OTHR at Jindalee and continues to use it.
    It raises: Prospects for tsunami detection and characterisation with HF skywave radar.
    It can also be used to track meteors:
    Method of meteor trail impulsive interference suppression in OTHR
    Jindalee is considered one of:
    The seven engineering wonders – the over the horizon radar ABC Northern Territory

    The equipment used is extremely sensitive, due to the level of accuracy that is need to detect objects that are moving such far distances away. The facility at Jindalee is a series of antennas that stretch over 3.4 kilometres. . . .
    It has even been suggested that the OTHR at Jindalee has the capability of interpreting what type of aircraft is taking-off at Singapore international airport, be it a Boeing 737 or 747, the facility is estimated to be this accurate. . . .
    OTHR technology can also be used to monitor illegal boats as well, as the technology has been perfected to the point where it also has the capability to observe small vessels on the water.

    For background see:
    Jindalee Over-the-horizon Radar Network (JORN) (Australia), Intelligence systems – Surveillance and reconnaissance, Jane’s
    The Development of Over-the-Horizon Radar
    in Australia
    D.H. Sinnott
    It continues to be enhanced: In-service enhancements of the Jindalee over-the-horizon radars
    The ability to track “Stealth” aircraft and rogue missile launches may renew interest in OTHR:

    The radar works by transmitting signals to the ionosphere which reflects them to the ground. This gives the Jindalee radars an added ability to detect stealth aircrafts. Stealth aircrafts are designed to defeat conventional radars from head-on, but not so for reflected waves from the ionosphere above, which is the concept upon which OTH radars are designed upon. Jindalee is also reputed to possess another capability – the ability to detect aircraft wake turbulence regardless of whether it is stealth or not. . . .
    The Jindalee network is deployed in Queensland and Western Australia, and is designed to monitor air and sea activity within 37,000 square km of coastline and ocean, acting as a security net that covers Australia’s northern approaches. One significant use of Jindalee is in thedetection of boats landing in the northern shores of Australia.
    Jindalee has another capability which will make it a vital component of the anti-ballistic missile defence shield as a missile detector – the ability to detect missile launches from ‘rogue’ states and track the trajectory of the missile so that it can be intercepted. Jindalee is now part of an American-Australian collaboration on an anti-missile defence system which involves detection of ballistic missiles by radar and their destruction by naval destroyers.

    A safety net for securing the South China Sea New Asia Republic April 24, 2011
    See also the A Lesson from Risk Management of the Jindalee Operational Radar Network (JORN)
    With suitable processing, it can be used to detect small aircraft.
    Detection of aircraft by high frequency sky wave radar under auroral clutter-limited conditions
    PS For those concerned, all this information is publicly available!

  12. But what are the trapezoids for? Did I miss something? I didn’t catch an explanation of their actual role.

  13. Ric @ 5:01 An air defense specialist has whispered in my ear that your explanation is very good. I thank D. Hagen and everyone for a very informative discussion. Was P’stra blessed per Weyerts Ohms?
    ===========

  14. Is there some connection here with HAARP (High Frequency Active Auroral Research Program)? It is based in Alaska, with another outpost in Norway.
    One of its activities seems to be heating the ionosphere… for research, obviously…
    Could possibly account for the greenhouse effect… (sarc?)
    [Reply: Just so you know, HAARP is one of the verboten subjects in the site Policy. ~dbs, mod.]

  15. David L. Hagen says:
    May 7, 2011 at 10:14 am re Australian Jindalee –
    Yep, and all that too, but some of those guys in other countries sometimes object to being told about Australians doing things better, like punching above our weight in Nobel Prizes, medical research, cutting edge rail freight, Olympic Games Gold, the best International airline, the world’s best Pommie shop stewards and a sense of humour that is incomprehensible to people from many other countries.

  16. JC says:
    May 7, 2011 at 10:18 am
    But what are the trapezoids for? Did I miss something? I didn’t catch an explanation of their actual role.

    That’s the shape of the radar array. The radar ‘dish’, in other words. Unlike other run of the mill radars these ones look only in one direction. Think of Arecibo radio telescope.
    And, just like telescopes, the bigger the better.

  17. Geoff Sherrington says:
    May 8, 2011 at 1:56 am

    David L. Hagen says:
    May 7, 2011 at 10:14 am re Australian Jindalee –
    Yep, and all that too, but some of those guys in other countries sometimes object to being told about Australians doing things better, like punching above our weight in Nobel Prizes, medical research, cutting edge rail freight, Olympic Games Gold, the best International airline, the world’s best Pommie shop stewards and a sense of humour that is incomprehensible to people from many other countries.

    Ah, the good old cultural cringe! Don’t forget we also have world class cyclones, floods and bush fires here.
    We are light on conspiracy theories, though. That is the American way.

  18. sHx: well, sorta. The antennas don’t move, but the radar “beam” does, by timing the phase of the signal(s). It’s complicated 🙂
    The trapezoids are cleared areas in front of the antennas, which are built in a straight line along the east edge of the clearing (in the ones pictured above). The cleared areas are or were covered with metal matting to provide a better ground plane for the antennas.
    If they had it to do over again, the transmitting antenna would probably be much smaller and the receive antennas larger and (possibly) somewhat curved. What wouldn’t be visible is that the receive antennas would be broken into small segments, each with its own receiver; the signals from the segments would be combined using computers to discern individual targets. That’s the way the Australian Jindaloo system, which as noted above works very well, is evolving.

  19. [Reply: Just so you know, HAARP is one of the verboten subjects in the site Policy. ~dbs, mod.]
    My apologies for this transgression.
    Prior to posting I had not read the site Policy section. I have now.
    M.

  20. The things I learn here. Several years ago, I was loaned to the DOD to do classified work and saw this type of radar at one base. Didn’t look like traditional radar and never asked what it was for since I didn’t have a need to know… now I know.
    Kforestcat

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