Updated

The Pentagon is rushing to Iraq a new device that creates a "virtual microphone" in the air to help detect the origin of sniper gunfire.

Tony Tether, director of the Defense Advanced Projects Research Agency (search), said Wednesday that the Pentagon also will use in Iraq a new electronic-detection device that could help pinpoint cell phones or pagers, which sometimes are used to detonate homemade bombs aimed at U.S. troops.

"They're not going to be 100 percent solutions," he said, but if they help even a little bit they may slow the anti-American resistance in Iraq.

Although makeshift bombs used against vehicle convoys are a bigger problem for American troops in Iraq than snipers (search), the sniper threat is problematic because the U.S. military has no reliable means of determining the origin of sniper gunfire.

"One of the problems we seem to be having is that people in Iraq can almost do anything they want and get away with it," Tether said. "We don't really have a good way to respond. So what we're trying to do is come up with technology that will at least make someone hesitate."

Tether said the "virtual microphone" is created by a laser fired from the ground. It detects motion of air particles, enabling technicians to calculate the origin of the gunfire.

The ground-based laser will be tested soon at Camp Pendleton (search), Calif., and probably will be available for use in Iraq within four months, Tether said.