GPSによる陸上航法の機能強化について

抄録

NAVSTAR/GPS is now drawing the attention of the whole world as a global infrastructure for navigation, traffic control and search and rescue of almost mobile vehicles around the world. However, there are some problems in the application of GPS at stand alone. First, GPS navigation accuracy will be intentionally degraded to protect from military abuse by the countries in disputes. Second, in the land mobile application of GPS, the view field of satellites is restricted by buildings, trees or mountains, so navigation data are lost or turn inaccurate frequently. In this paper, several methods to solve the above mentioned problems are investigated and the navigation performance of these methods is verified by carrying out the computer simulation study. The use of high precision quartz as GPS reciever's clocks, vehicle velocity data derived from delta ranges, distance data derived from vehicle speed and direction, or additional range data obtained from satellites other than GPS are considered as the effective ways to improve the accuracy and reliability of satellite navigation.