WooHoo Wild Weasel party!!!
Its best to stay out of HARM's way!
Posted on 01/26/2003 11:33:50 AM PST by ex-Texan
Weapon of the Week: The Russki Jammer -- Just How Effective Is It ... ?
by George Smith
With little of substance to report thanks to the secrecy fetish of the Bush administration, bored mainstream war journalists occasionally "discover" news that departs significantly from both common sense and reality. Such was the case last week with the story of Iraq's Global Positioning System jammers, leaked by an anonymous intelligence official either profoundly ignorant of the capability of U.S. weaponry or purposely planting disinformation.
The GPS jammer, a cheap piece of Russian electronic junk peddled on the global arms market since 1997 by a firm called Aviaconversia, was said by Fox, Newsday, and others to be a key part of Saddam's war strategy. The U.S. military's Joint Direct Attack Munition smart bombs, reliant upon GPS updates for aiming, would end up blasting civilian targets. Displays of the carnage would raise the ire of international observers, increasing pressure on the United States.
So much for the hype. Left less obvious was that Aviaconversia's jammer sales pitch was aimed at suckers—specifically those in Iraq. Photos of the device furnished by the Air Force's Air Intelligence Agency are accompanied by the firm's diagram of how it might be installed around that country.
The Defense Department can't be quaking over this one.
JDAMs were designed to overcome any poor man's GPS jammers. Each bomb is guided by a GPS and an "inertial navigating system"—or INS—working together. If the GPS is unreliable, the second control still guides it in. With GPS, a JDAM hits within about three meters of its target. With only the inertial navigation, accuracy decreases but not so it matters. In addition, five years ago Boeing developed an anti-jamming package for the JDAM that assured frightening capability. We paid $6 million for it.
In any case, JDAMs are large bombs. Whether they land three or six meters from their target is irrelevant to anything close by. Jammed by a Russki contraption or not, they explode very near where they're supposed to—always smashing things. Look out below!
In light of the story's evident folly, it cannot be ruled out that the "news" was intentionally fostered by the Pentagon. It is well known that employment of jamming immediately reveals the location of the jammer, painting a bull's eye on him. Good news for Uncle Sam's regime-change plans if one gets used on top of the Iraqi presidential command bunker.
When satellite navigation was introduced, many countries threw in an error factor which was randomly changed on a daily basis, so that Saddam types couldn't drop a big one, say right on top of the Eiffel Tower or the cap of the Washington Monument.
As the tech improved. most of the world realized the folly of this and just quietly gave up. Not the Russkis. Road Maps are classified. The Phone Book is classified. Freighters coming in must absolutely have a local pilot who commos on secret frequencies and knows how to avoid trap buoys. They have no yachtsmen or civil aviation and no highways between major towns.
Yes, folks, years after the commies have supposedly gone, Russia has an infrastructure which went out of style in the West around 1450AD. Someone should tell the Czar. In this regard, the Russkis were better off in 1917 ... bigger wheat harvest and at least you could get where you were going ... maybe all the way to the US if you were lucky.
WooHoo Wild Weasel party!!!
Its best to stay out of HARM's way!
They may not work, but the workmanship is sure #1.
Sodom, we'll save the HARMs for your fire control emitters, for everything else, static will do.
Saddam ain't so smart.
The latest issue of GPS WORLD had an article about tracking down interference to GPS signals. It seems three yachts in a yacht basin had TV boosters attached to their TV antennas. All three were faulty, and emitted signals in the GPS band that kept other watercraft from using GPS within a range of several kilometers. It took weeks to hunt down the sources of the interference. Evidently it doesn't take much of a signal to black out the GPS signal, and even if you know the GPS is being jammed, it's hard to locate the source. I have no idea what the significance of this is for jamming GPS-directed bombs, but it indicates the Russian jammers may not be completely useless, especially for preventing ground patrols to use GPS to locate targets.
Actually, fifteen years ago, they did get a small taste of civil aviation.
But wouldn't these things need to send out a radio signal that would provide a homing beaconYou *really* have been out-of-the-loop for awhile regarding military electronics.
GPS does NOT work like the old long wave beacons/ADF gear or even VOR - it works by actively measuring the time difference/doppler shift of a small number (3 for 2D, 4 or more for 3D position) of satellites.
To 'spoof' GPS would require the accurate 'spoofing' of 4 or more spread-spectrum signals representing the GPS pseudo-random code sequence - accurately - and at a signal strength *stronger*, at altitude and range, than what the real birds ...
It would be doable - but it would be as cheap (probably) as these cheap jammers the Russion sold ...
In close proximity a strong CW source in or out-of-band can 'block' (desense) a GPS receiver. I have seen some effects from PCS 'cellular' sites operating at 1800 MHz to some of the earlier '90's receivers that didn't have enough front-end filter selectivity ...
More often it is these so-called 'active' TV antennas, both settop types and RV roof-mounted types (I have tracked down over 4 in my area alone) -
- they are notorious for oscillating (esp. the RV types when on in the down or 'stow' position) and affecting UHF 2-way 'repeaters' (both business band and amatuer 2-way repeater) in the 440 to 470 MHz area ...
A little work with an HT that has an S-meter and a Yagi points 'em out pretty quick!
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