An Analysis of Effect on Differential GPS Correction by GPS Satellite Clock Failure

Abstract

The importance of the Global Position System (GPS) is becoming larger and larger since it is one of the Global Navigation Satellite Systems (GNSS) and is regarded as a national infrastructure in the field of position, navigation and timing. Applications of the GPS include military, surveying, geodesy, car navigation, marine system, aircraft system and network synchronization. In recent year, the applications expand into natural science applications, architecture, communication, weather forecasting, and LBS (Location Based Service). Dependency of the GPS will be rapidly increasing as the application grows, Nowadays many researches avoiding and/or minimizing economic loss caused by unexpected fault of the GNSS are being carried out because GNSS fault can give a large impact on social security system as well as economic system. Especially, it is required much more position accuracy and integrity function to use the GNSS in the marine and aircraft related areas. In order to satisfy requirement, we can use augmentation system as Differential Global Positioning System (DGPS). Recently, importance of integrity monitoring function is becoming larger and larger, because the GNSS fault can give a large impact in position accuracy. GPS satellite failure effects on all GPS receiver and it is not easy to recover failed GPS satellite in the fast time. GPS satellite failure classifies into signal generator failure, satellite clock failure, and signal spectrum failure. Especially, GPS satellite clock failure has effect on all of the GPS signal generator part. This paper analyzes effects on performance of GPS receiver due to GPS satellite clock failure. And to analyze effect on pseudorange correction (PRC) in DGPS reference station due to GPS satellite clock failure, GPS receiver for DGPS reference station measures PRC using GPS simulator.