Patent ID: 7269512

Claim:
An information processing apparatus for measuring a current position by using a radio wave from a single GPS satellite, comprising: a Doppler shift measurement unit obtaining a Doppler shift in a freguency of the radio wave from the satellite; a distance measurement unit obtaining a pseudo-distance between the satellite and a measuring point by using a signal from the satellite; an arithmetic calculation unit calculating a position of the measuring point by using the Doppler shift combined with the pseudo-distance, thereby obtaining the position of the measuring point with high precision using only the single GPS satellite when a clock of the satellite is synchronous with a clock of the information processing apparatus; and a data acquisition unit acguiring navigation data of the satellite, wherein said arithmetic calculation unit obtains a position of the satellite and a relative velocity between the measuring point and the satellite from the navigation data, and calculates the position of the measuring point by using the obtained position and relative velocity of the satellite, the Doppler shift and the pseudo-distance, and wherein said Doppler shift measurement unit includes a correlator which generates a code shift amount by obtaining a correlation value between a signal from said satellite and a prescribed code, and obtains said Doppler shift from an output of the correlator; and said distance measurement unit obtains said pseudo-distance from the code shift amount generated by the correlator.