Defence

Lockheed Martin is to equip US Army unmanned air vehicles with the ability to see targets through camouflage using a low-frequency synthetic-aperture radar that has demonstrated its ability to penetrate foliage and other forms of concealment.

Under the 32-month, $40 million tactical reconnaissance and counter-concealment radar, or Tracer contract, Lockheed will build two podded VHF/UHF SAR sensors for installation on General Atomics Predator-family UAVs for six months of flight testing, says programme manager Robert Robinson. The company will also supply a radar workstation for use with the Predator ground-control station.

This phase will be followed by two years of operational demonstrations within and outside the continental USA, including expected deployment to Afghanistan or Iraq. A Beechcraft RC-12 fitted with a dual-band low-frequency SAR under the US Defense Advanced Research Projects Agency's foliage-penetration (Fopen) technology demonstration is being used to develop operating concepts for the sensor.

The Fopen radar "blasts" the target with wideband energy and processes the entire VHF/UHF band to see man-made objects though foliage and camouflage. The resulting imagery requires new interpretation techniques because its output is different to conventional X-band SAR, says Robinson, and more like an electro-optical sensor. The system can detect changes and several passes at different aspects and altitudes can create a three-dimensional target image using "volumetric SAR".