Trimble Navigation has been given Pentagon clearance to start production of the Selective Availability Anti-Spoofing Module (SAASM) for military Global Positioning System (GPS) receivers used in aircraft, ships, vehicles, missiles and hand-held devices. The Pentagon's GPS Program Office has mandated that all military receivers delivered after October 1, 2002, must have an anti-spoofing capability. The first SAASM-equipped devices will be delivered next month, and will be available for delivery to U.S. forces and authorised allies. SAASM technology has been under development since 1992. It is related to the Pentagon's Navigation Warfare project, which is aimed at developing a second-generation GPS, which is more resistant to jamming.