POSITION DETECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To measure a receiving position with a comparatively high accuracy by using both the GPS technique and the position detection technique of a PHS terminal in a PHS public network. SOLUTION: A GPS receiving part 12 receives a GPS signal from a GPS satellite, and a PHS receiving part 22 can communicate with a PHS base station 2. A GPS position measurement calculation part 13 finds a first probability density function regarding the measurement position by the GPS signals from three or more GPS satellites received by the GPS receiving part 12. A PHS radio wave intensity measurement part 23 finds a second probability density function regarding the measurement position based on the position of the PHS base station 2 communicating with the PHS receiving part 22 and the receiving intensity. A present position estimating part 31 determines the measurement position by finding the position where the maximum likelihood value can be obtained from the first and second probability density functions.