Studying the Performance of Global Navigation Satellite Systems

60 GPS World June 2002 www.gpsworld.com Both users and researchers benefit greatly from design computations which allow them to study the performance of a positioning system. Users need to know how they can meet the accuracy requirements for a specific application at hand. They need this information in order to set up the positioning system for that application. Researchers may be interested in the system’s performance to study, for example, the improvements which future global navigation satellite systems (GNSSs, modernized GPS and Galileo) will bring or to compare systems. Parameters which are good predictors of performance and which can be computed without actual observations include the internal and external reliability, the carrier-phase integer ambiguity resolution success rates, and the dilution of precision (DOP) values. All of these design parameters depend on the positioning system, the observation model, and the time and location of measurement. Therefore, it is very useful to study Studying the Performance of Global Navigation Satellite Systems A New Software Tool