HAMPTON, Va. (AP) -- The Air Force is expanding surveillance and intelligence operations at Langley Air Force Base that find enemy troops and roadside bombs in Iraq and Afghanistan.

The service will spend $42 million for a new facility to analyze video and data from spy planes and aerial drones that is interpreted by airmen at Langley and fed back to troops on the battlefield.

The planned two-story, 144,000-square-foot building is expected to be finished in March 2009 and will allow the 497th Intelligence Group to increase the number of analysts to 400, from 70.

Col. Dan Johnson, the unit's commanding officer, said the expansion reflects the military's growing reliance on the intelligence unit. The network's abilities have grown in the past six years to allow airmen and equipment to permanently operate in safe, remote locations.

"You don't have to put people in harm's way," Johnson said.

Originally intelligence squadrons were designed to work near combat operations overseas, but improvements in network technology and security concerns have kept the units on domestic bases.

The Air Force has five similar intelligence hubs, with the largest facilities at Langley and Beale Air Force Base in California.

At Langley, a collection of portable trailers now housing the unit fill a secured airplane hangar where analysts and support staff monitor and sift through data from U-2, Global Hawk and Predator surveillance planes. Data is pulled together around the clock and send it to computers used by ground troops with only a short delay.

The center is "a little bit crowded," said Lt. Col. Keith Andrews, an intelligence officer, and the new site will make it easier to gather and deliver the information.

Technical Sgt. Gregory Artis, a computer technician who has been with the unit for three years, has seen the amount of equipment and personnel increase, but said, "we're running out of room to grow."

(Copyright 2007 by The Associated Press.  All Rights Reserved.)