There is a war being fought between bombers and jammers. The bombers plant bombs and set them off. The jammers look for way to defeat the bombers. The war has been fought mostly in the battlefield of electromagnetic frequencies. It morphs quickly and fewer wars have seen quicker countermeasures. An article by Noah Schachtman in Wired Magazine’s Danger Room talks about the silent war. Here are some technology highlights summed up.
Early IEDs were called Spiders. These were Soviet era munitions say a 152mm artillery shell that was wired to firing circuits. The Firing circuits were wired to a Japan InstaLite fluorescent lamps that were wired to signal receivers. This allowed to attacker to plant the bomb, and stay a football field away and set it off.
The Shortstop. This was an electronic counter measure. It worked like this. Artillery often uses proximity fuses. That is a device that emits a strong electromagnetic signal while it is flying. Once it gets close to a target, the target begins reflecting the signal back. The fuse is set to go off when the signal strength is at a certain level So if the shell is 100 feet from the target, it might start receiving the signal bouncing off the target. As it gets nearer the signal increases. Users can set the fuse to go off just in front of the target, so it’s explosive yield isn’t diminished as it would by exploding after it penetrates the target and exploding behind it. The Shortstop monitors and emits the return frequency by itself hoping to prematurely detonate shells.
The Acorn. This was a signal jammer emitter that could be mounted on the front of a truck, but it had only a protective range of 30 meters and had to be squawking all day long.
The Warlock was a tweaked Shortstop that tried to fire off IEDs well in front of vehicles. Made by EOD Corporation, it was too slow to be effective. In the time it could take a bomber to push the button on a garage door opener, the Warlock was still recording and adjusting to send out the right frequency. But the Warlock was adjusted and improved. Any ECM is better than no ECM. So the Army bought a wearable Warlock called Blue designed to protect the infantry soldier. The Army also bought Warlock Reds, designed to block out low power key fob detonators. From time to time, Warlock Reds and Warlock Greens would detect each other and jam each other.
The EA-6B Prowler ECM pods were powerful enough to set off bombs. Not very efficient to have to launch a Navy aircraft to go feet dry and knock out an IED.
By 2006, 15,000 soldiers had been wounded by IEDs. This made the IED a weapon about as effective as they would have been had they had a decent army to begin with. There were some EMF band successes but the IEDers stayed ahead of the coalition troops for the most part. By 2006 they had started using shaped charges that could penetrate thick armor.
The US jumped ahead by organizing the panoply of radio frequencies used by the insurgents and the panoply and a half of jammers frequencies. Warlock Red and Blue were made to work together, for instance. The Marines used a system called Chameleon that weighed over 100 pounds but mounted on a Humvee it worked pretty well.
Warlock Duke was created to fool digital hand held signal generators like cell phones and new walkie talkies. EOD robots were effective ways of dismantling bombs, and close air strikes could defeat bombers. Also, new blast resistant vehicles were slowing the casualty rate way down.
By the end of 2007, the US was getting ahead of the Iraqi bomb makers. We began making CVRJ, or Crew Vehicle receiver/jammer. These could stop a number of radio frequency jammers and all at the same time. Today’s jammers are networked so each unit’s various jammers operate together more efficiently. Think of it as a sort JSTARS for jammers.
The US spends billions in this war to stay ahead of the bombers. In Afghanistan, the IED war has expanded in a different way. Now bombers are going back to simpler, more effective ways of setting off bombs remotely: copper wiring.
And the beat goes on.
Source: Wired, Danger Room, Washington Post