Out of the Black.

Experiments in the Nevada desert are using unmanned aircraft to find the exact location of enemy electronic emissions, such as the mobile phone of a terrorist in a fast-moving auto. The U.S. Air Force researchers say they've been able to locate such targets, as well as mobile missile systems, within tens of meters and often in less than a minute, which makes them vulnerable to attack before they can flee surveillance. Such tasks, until now, were the exclusive purview of classified systems on the Pentagon's small fleets of U-2, RC-135 Rivet Joint and other manned, intelligence-gathering aircraft.