A seamless tracking solution for indoor and outdoor position location

The paper discusses various techniques that have emerged for estimation of location and tracking of stationary and mobile objects both in the open terrain as well as inside a building. For outdoor applications, Global Positioning System (GPS) has proven reliable and accurate. For urban and indoor applications various RF based ranging/positioning techniques have been investigated. Recently modifications to GPS for indoor applications have been proposed. For example, network assisted - GPS (A-GPS) provides via a cellular data link, additional ephemeris to stand alone GPS for aiding. Increase in the indoor GPS receiver sensitivity has been proposed by providing a large number of correlators. A number of other sensors such as inertial measurement unit (IMU), enhanced dead reckoning devices, miniature or micro electromechanical systems (MEMS) could come to aid for durations following the loss of GPS. In addition path constraints based on the indoor environment may assist in determining accurately the position. The objective of our research has been to provide a seamless, sensor fused tracking system in which data from various sensors may be processed using Kalman filters or more general particle filtering algorithms. Interest is in the applicability of these techniques to develop a military soldier wearable system for use in combat training systems for military operations in urban terrain (MOUT)