Patent ID: 7423584
Filing Date: 2008-09-09
Classification: G01S

Abstract:
1. A terminal device which locates a position using a satellite signal from a satellite positioning system (SPS) satellite, the terminal device comprising: a signal search section which can search for the satellite signal in a basic mode, in which the signal search section searches for the satellite signal by performing a correlation process over a predetermined first accumulation time within a predetermined frequency range in units of search frequencies at specific intervals, and a special mode, in which the signal search section searches for the satellite signal by performing the correlation process over a predetermined second accumulation time longer than the first accumulation time, the signal search section searching for the satellite signal in the special mode at the search frequency and frequencies differing from the search frequency by a specific frequency which is less than the interval of the search frequencies and specified based on a drift of a reference oscillator of the terminal device within the second accumulation time, and determining a search result in the special mode based on search results at the search frequency and the frequencies differing from the search frequency by the specific frequency.