Being the satellite navigation additional strength system which makes the determination precision of GPS IMPROVE which

摘要

PROBLEM TO BE SOLVED: To allow an optimum transmission timing to be set even in a ground uplink station in backup system and smoothly perform changing operation of site.;SOLUTION: The ground uplink station 1, when operated as a backup system, makes communication with a stationary satellite 3 in an idle time of communication between a ground uplink station 2 in a primary system and the stationary satellite 3 paired therewith, thereby, it measures an optimum delay time and sets the transmission timing for a message to be transmitted from the station to the stationary satellite 3 to be adequate for a transmission timing for the stationary satellite 3.;COPYRIGHT: (C)2003,JPO