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

Was it about to reveal something that “wasn’t there”?

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.

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.

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

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.

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)

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.]

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.

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.

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