SUO/SAS geolocation: land navigation using multiple integrated sensors

The small unit operations/situation awareness system (SUO/SAS) was developed by the Defense Advanced Research Project Agency (DARPA) to address the future needs of individual soldiers on an increasingly complex and lethal battlefield. As tactical operations have shifted toward smaller units, the importance of force multipliers has concomitantly increased. One such force multiplier is the ability of a soldier operating in a restricted environment to constantly know the location of both friendly and enemy soldiers. The SUO/SAS geolocation system was designed to provide continuous reliable geolocation data in the many different restrictive environments which might be encountered by a soldier in modern warfare. This system integrates multiple sensors to provide a continuous solution in multiple environments. For open environments, the geolocation system may rely on GPS. But for those areas (such as inside a building) where GPS signals are nut available, a combination of other sensors are provided. Range measurements are provided by time-of-arrival (TOA) transceivers, and altitude information is provided by a barometric altimeter. Velocity is maintained via an IMU, and heading information is provided by a digital magnetic compass. All of this information is integrated into a single navigation Kalman filter to provide an optimal solution. This paper presents the architecture of the SUO/SAS geolocation system and characterization testing results.