RELATIVE POSITION DETECTING SYSTEM AND RELATIVE POSITION DETECTING DEVICE

摘要

PROBLEM TO BE SOLVED: To quickly measure a simple differential global position system(DGPS) and raise accuracy by selecting a satellite to be used for position measurement based on the trend of common use of a position measurement satellite, directing the first and second position measurement means and specifying a position measurement satellite. SOLUTION: A wireless telephone 160 receives the first position data sent from a wireless telephone 210 and sends control signal controlling a GPS receiver 270 to the wireless telephone 210. A CPU 110 calculates the relative position of a relative position value detector 200 to a relative position detector 100 based on the second position data measured with a GPS receiver 170 and the first position data received with the wireless telephone 160. The CPU 110 calculates common utility degree of a position measurement satellite used commonly by GPS receivers 270 and 170 for every position measurement satellite. Control signal is forwarded to at least one of GPS receivers 270 and 170 so that the CPU 110 selects and uses a position measurement satellite of high common utility degree.