You sure have some
weird stuff in the desert out there. (What the heck is that, anyway?
)
Looks like a RADAR test range to me. Possibly early over-the-horizon backscatter variety. Here's the end of the range next to the runway you were centered on, zoomed in. Note what you can tell by the "antenna" structure by the shadow.
http://bit.ly/gZbC5N
The Russians built a monster, of something that looks quite similar...
http://englishrussia.com/index.php/2008/04/28/duga-the-steel-giant-near-chernobyl/
I didn't become a ham radio operator until 1991, but I heard the "Russian Woodpecker" and recordings from other hams I had met prior to me getting a station set up, and my first license...
http://en.wikipedia.org/wiki/Russian_Woodpecker
More general stuff...
http://en.wikipedia.org/wiki/Over-the-horizon_radar
The more modern "version"...
http://en.wikipedia.org/wiki/PAVE_PAWS
A few years ago the Air Force demanded that Amateur Radio operators on UHF (which is not technically an Amateur band, but is a shared band with the U.S. Military as Primary user, and Amateur Radio listed as a Secondary user "to be treated as Primary whenever possible" by NTIA), had to lower their transmitter power output significantly within a certain radius of these stations at Beale AFB, Cape Cod Air Force Station.
As one RF engineering professor acquaintance put it... "The only two ways to 'see' a reflected RF signal better are, a) raise the transmitter power for a better reflection, or b) make a significant change to the receiver sensitivity or selectivity. So if the Air Force already published that they could see something the size of 'X' with PAVE PAWS* and you know the amount they're requesting the Amateurs to lower their signal levels, you can do the reverse math and tell exactly how small an object they're looking for and/or make an educated guess about how far away it is from the receiver."
* The published numbers are probably disinformation and the true capability of the system could be lower or higher, but is likely higher, since it's still in operation today.
So, I did the math. The target is really small. And it's probably outside the atmosphere of the planet.
There's an inverse relationship with size and distance in reflective RF tracking, so the smaller the object, the closer it needs to be for the same reflection... so you have to make some educated guesses within the ranges available... but they're probably not looking for school-bus sized objects outside of Earth orbit... if you know what I'm saying.
So, considering that with modern computers and controls, the venerable old phased array can probably re-aquire and switch targets way faster than most humans can visually process the data... probably a whole lot of "somethings" needed to be seen.
Then you watch the news, and notice that the rules for Amateurs went in around this date...
http://www.space.com/3415-china-anti-satellite-test-worrisome-debris-cloud-circles-earth.html
Well, anywhoo... not much of a mystery, really.
I've always had an interest in this stuff.
Related but not directly to this, is that the State of Colorado recently put a "Wide-Area Multilateralization" system in the Aspen valley for seeing aircraft on approaches.
Way cheaper than a RADAR, no moving parts, just a bunch of receivers scattered around at known ground locations, a transmitter to trigger your aircraft's transponder, and a very very accurate clock to tell "when" the receivers each heard your transponder's reply, gives the exact location of your aircraft from you having nothing but the usually required transponder on board.
It went operational some time ago, and is why Aspen is a "secondary targets only, no primary RADAR" facility. WAM was cheap...
I have photos a friend took of all the boxes... they are standard NEMA boxes on poles, with a couple of fiberglass "stick" antennas, a good ground rod and grounding system (lightning takes out more of our radio gear in the mountains than anything else around here, and 2nd place is bad power -- also caused by lightning) and that's about it.
They obviously had to be located at various places and the communications back to the central computer had to be timed and the delays from each site accounted for, but that's about it.
FAA approved it for use by Denver Center (ZDV) quite a while back, and integrated the WAM data into the same "RADAR" screens the controllers have always looked at... they don't even really need to know they're not looking at a traditional RADAR return. How it got there is immaterial to them.
Projects like WAM for the Aspen valley are so elegant, that they make ADS-B look expensive and silly. Big time. Everyone knows the game is rigged toward ADS-B here, and making the aircraft transmit their own locations. (Via a non-encrypted channel, I might add... think that's not a problem waiting to happen?)
WAM has some pretty cool potential to bring "RADAR" coverage to areas where it was far too expensive to deploy a traditional rotating 60's vintage array, or an 80's vintage phased-array "true RADAR" system.
But do you read anything about it in the Aviation press? Not much. They're pushin' ADS-B which is basically 80's vintage low-speed data with a defined block/packet size and defined data fields.
ADS-B is "high drag, low speed" as a different friend would say.
But there's an awful lot of money and government bureaucracy shoving that boulder uphill.
Anyway, you got me thinkin' about cool RADAR toys again Kent... hadn't thought about that since the Air Force kicked some friends off of UHF a few years back, as mentioned above.
