Demand is growing for systems that enable the centralized monitoring of the location of moving people or objects, such as position management systems for commercial vehicles, personal location systems for wandering aged people, and emergency notification systems. The basic requirements of such systems include the detection by the moving object or person of its own position and transmission of this position information to the center. In response to this need, a system that is capable of precision tracking of moving entities has been developed. This system is based on the introduction of a Differential Global Positioning System (DGPS) which provides high precision position detection. Attempts to develop a method for reducing the quantity of data transmitted from the mobile station to the center have also been made. Success in shortening the data describing a location from 327 bits to 200 bits by reducing the positioning time and pseudo-range data and obtaining good position correction results by means of DGPS is reported. (A*)
Abstract