The U.S. Army has ordered 37 Backscatter radars, mounted in trailers designed to be moved over rough terrain in Afghanistan. The radars are used to examine vehicles, especially trucks, and reveal weapons or hidden passengers. In the last seven years, the over 300 of these radars have been ordered, and over a hundred have been used by the military in Iraq and Afghanistan.
The backscatter radar scanners are one of the more successful new counter-terrorism tools. The radars are basically a new, and portable, version of an old technology. The old tech is backscatter, over the horizon, radar. Originally developed during the Cold War, to provide a long range radar, the new version is a portable (carried in a van) version called the "Ruggedized Detection Imaging Modules" (RDIM).
The Z Backscatter technology, which makes this all work, is basically X-Ray machines that can see through clothing, and inside vehicles, and distinguish between organic and inorganic material. RDIM provides a photo quality image in seconds. The subject has to stand in front of the RDIM. Now normally, you could check someone for bombs on their person by just patting them down. But suicide bombers tend to set off their bombs when they perceive a pat-down coming. So a RDIM could be set up so that the operator and the subjects are far enough away from each other that, if a suicide bomber is encountered, you only lose the machine. That can be expensive, for these rigs go for about $1.3 million dollars each, and cost over $10,000 a month to maintain. The Department of Defense began with four RDIMs in early 2005, but quickly obtained more when it was discovered how useful the units are.
Foreign countries, particularly in South America and the Middle East have been ordering a lot of them, especially for providing security for VIPs and critical locations. Z Backscatter technology is the most expensive, non-intrusive and thorough kind of security you can get. But as the price continues to fall (Z Backscatter units cost about a third less than they did four years ago), more of it will be used.