Lockheed Martin (NYSE:LMT) won a sizable Department of Defense contract Thursday. In modification of a preexisting firm-fixed-price contract, the Pentagon will pay Lockheed $206.9 million to supply additional AN/TPQ-53 radar systems and corresponding spare parts. In total, Lockheed's underlying contract value now rises past $605 million.

Although Lockheed is primarily considered a military aerospace stock, the AN/TPQ-53 is actually a radar system for ground troops, and it's the U.S. Army buying it, not the Air Force.

Lockheed describes the system as a "counterfire target acquisition radar." Mounted on a mobile medium tactical vehicle, it detects, classifies, tracks, and determines the location of enemy indirect fire such as incoming mortar or artillery rounds. Once the location of the hostile fire has been determined, the radar can then be used to launch counterbattery fire to suppress and destroy the firing artillery unit.