Friday, October 08, 2004

"ANTITERROR: EEs seek way to ID triggers of Iraq's IEDs"
One of the United States' largest electromagnetic-emission "shielding" labs has switched roles to help armed-services personnel detect bombs. The University of Missouri at Rolla's Electromagnetic Compatibility Laboratory is trying to sense, rather than shield, emissions from the triggering mechanisms in improvised explosive devices (IEDs), which could alert troops to unexploded munitions. EE professor Todd Hubing and assistant professor Daryl Beetner said they saw the benefit of reorienting their work when visiting nearby Fort Leonard Wood, Mo., where they viewed IED training tapes. They saw that the emissions from many command-initiated IEDs, which are normally placed at the side of a road, were sufficient to be sensed from a distance. Hubing and Beetner immediately began thinking that it would be possible to detect the signature of electronically triggered IEDs, even when they are not transmitting, but merely "waiting" beside a road in Iraq to receive a detonation signal. "We started looking at unintended electromagnetic emission from improvised explosive devices and found that if we shifted their frequency to the audio range, almost anyone could recognize their distinctive 'signature' sound," Beetner said. "And if you can hear the difference, then there has got to be a way to build a device for soldiers to use that detects radio-controlled IEDs from a distance." That's the opposite of the lab's typical practice. "At our lab we try to shield devices, so we know just how very difficult it is to make an electronic device not emit electromagnetic energy � even when it's just a receiver," Beetner said. According to the engineers, sophisticated electronic devices like cell phones cannot be completely turned off � there is always active circuitry inside