Patent ID: 7142155

Claim:
A global positioning system (GPS) receiver comprising: a receiver operable to receive GPS satellite signals; a level determination section operable to determine whether or not a reception level of each of the GPS satellite signals received is approximately equal to or more than an associated reception level threshold; a positioning calculator operable to perform a position calculation using the GPS satellite signals that each satisfy the associated reception level threshold; a calculation determination section operable to determine whether or not the position calculation can be accurately performed based upon the GPS satellite signals that each satisfy the associated reception level threshold; a dilution of precision (DOP) value determination section operable to determine whether or not the position calculation satisfies a DOP threshold; and a threshold change processor operable to gradually relax at least one associated reception level threshold or the DOP threshold when the calculation determination section determines that the position calculation can not be accurately performed, or when the DOP value determination section determines that the DOP threshold is not satisfied.