Situation Aware Intelligent Geopositioning Equipment (SAIGE)

The Global Positioning System (GPS) has rapidly become an indispensable technology in both the military and civilian worlds, but its limitations are well-known to every GPS-guided driver who has ever gotten lost in an urban canyon, and its universality makes it a likely target of both simple and sophisticated electronic attacks in military operations. We describe a number of novel techniques for the design and implementation of GPS User Equipment (UE) that will improve the performance of the GPS receiver in weak-signal or other challenged environments. The foundation of this proposal is the technology of Cognitive Radio, extending the technology of Software-Defined Radio. A Cognitive Radio (CR) is a radio that can sense its operating environment and modify its behavior to accomplish its goals. Software-Defined Radio provides the capabilities to sense the RF signal environment and to modify the radio''s operation. A Cognitive Engine mediates between sensing and acting, applying defined rules and heuristics to determine appropriate responses to various challenges. We also describe a novel open-loop architecture for the GPS receiver that provides robust acquisition of weak and intermittent signals and a design that integrates the receiver with an Inertial Navigation module for tracking in very low Carrier/Noise regimes. BENEFIT: Accurate Position, Navigation, and Time information is indispensable to the contemporary warfighter, but current GPS equipment is vulnerable to unintentional and intentional jamming, spoofing, errors due to multipath effects, and difficulty acquiring and tracking signals in urban canyons and in valleys with obstructed sky visibility. Modern irregular warfare increasingly takes place in exactly the urban settings or mountainous terrain that present the greatest challenges to GPS effectiveness. An innovative receiver architecture and advanced signal-processing techniques can detect and counter those challenges. Software-Defined Radio and Cognitive Radio technologies provide the framework for identifying challenges and selecting the countering techniques that will best serve the warfighter and the mission. In addition, a system built in software can be upgraded, resized, and integrated with other tools. The ultimate goal of the SAIGE project is to create a family of Military GPS User Equipment in a range of form factors, from individual handheld to vehicle-mounted, that can be deployed to warfighters at realistic cost, that overcome the limitations of current GPS equipment in urban and mountain warfare without requiring special training, and that can operate in a crowded RF environment and detect and avoid jamming and spoofing.