March 2, 2012: The U.S. Air Force is sending its new TRACER Foliage Penetration Radar to South America for further testing. TRACER uses SAR (Synthetic Aperture Radar). SAR can distinguish small objects on the ground in search mode and then zero in at smaller resolution to get details (like someone carrying a rifle). SAR can see through storms, even sand storms, any time of day.

TRACER uses smaller but very powerful SAR and software that enables it to detect what is beneath thick foliage. TRACER is light enough to be carried by Predator UAVs and it will be tested in South American jungles, under many different weather conditions, to see just how accurate it is in realistic combat zone conditions. The predecessor of TRACER was too heavy for most UAVs. For example, Predator has a max payload of 204 kg (450 pounds) internally. This was insufficient for the existing FOPEN, Foliage Penetration Radar, that weighs over 250 kg, but it is enough to carry TRACER. FOPEN was developed in the 1990s and entered service in 2005. TRACER will soon replace it.

In the last few years U.S. firms have developed miniaturized SARs weighing as little as 1.3 kg (about three pounds) and taking up about as much space as a shoe box. Cheaper, smaller, and more powerful computers have helped reduce the size of SAR equipment over the last three decades (since SAR was first introduced). SAR is good for detecting vehicles and can penetrate clouds and sand storms to show a precise image of the landform below.