Patent ID: 7612713

Claim:
A first output position calculation method that calculates a first located position to be output after starting positioning when receiving satellite signals transmitted from positioning satellites and performing present position positioning calculations based on the received satellite signals, the method comprising: executing a positioning process that performs positioning calculations based on the received satellite signals to calculate a located position; changing a repetitive execution count of the positioning process; and determining a final located position calculated when the positioning process has been executed in a number corresponding to the repetitive execution count to be a first located position to be output, the executing of the positioning process including: selecting satellite sets based on the received satellite signals, each of the satellite sets being a combination of satellites used for a present positioning process; calculating present position candidates corresponding to the respective selected satellite sets using the satellite signals from the satellites included in the respective selected satellite sets; calculating APR (A Priori Residual) values of the respective selected satellite sets, the APR value being the sum of the square of the difference between 1) a pseudo-range and 2) an approximate distance of a target satellite of a target satellite set, the approximate distance being a distance between the target satellite and the present position candidate of the target satellite set; calculating an APR average value of the present positioning process by averaging the APR values of the respective satellite sets; selecting a present position candidate from the present position candidates corresponding to the respective satellite sets and determining the selected present position candidate to be a located position determined by the present positioning process; and the changing of the repetitive execution count including changing the repetitive execution count based on the APR average value.