GPS POSITION DETECTOR

PROBLEM TO BE SOLVED: To provide a GPS position detector equipped with a new function by which the radio-wave receiving condition of the GPS position detector is estimated on the basis of the output of an environment sensor and by which an integration processing operation can be selected and executed with reference to the matrix search processing operation of a GPS signal while the integration period of the integration processing operation is being changed over automatically. SOLUTION: The GPS position detector is provided with a GPS antenna 1, the environment sensor 11 which senses an ambient environment condition for estimating the reception strength of GPS radio waves and a GPS positioning processing part B which contains matrix search processing circuits 4, 5 for capturing a GPS satellite. The function which executes a prescribed integration processing operation is added to the circuits 4, 5, the integration processing operation is executed selectively according to the reception strength of the GPS radio waves estimated on the basis of the output of the environment sensor 11, the GPS radio waves from the GPS satellite are captured, and a navigation message is decoded.