摘要 |
PURPOSE:To facilitate the acquisition of a master station signal even in a region wherein S/N is bad, by sampling the master station signal in plural times by an acquisition timing based on a current position and a plurality of acquisition timings of slave stations discriminated according to these stations, and by accumulating and averaging the signal. CONSTITUTION:A current position is set through NNSS11 for setting the current position or an input key 9 and written in a buffer area of RAM71 of a microcomputer 7, or the like. A plurality of acquisition timings of slave station signals, acquired through a sampling circuit 4 and discriminated according to the stations by the computer 7, and a chain table GRI, etc. are also written in a slave station counter area TS1 of said RAM71, and the computer 7 computes the acquisition timing of a master station signal based on the same and makes this timing memorized in a master station counter area TM of RAM71. A real time counter 8, the circuit 4, etc. being controlled by this acquisition timing, the master station signal is sampled in plural times and accumulated and averaged later by the computer 7, and thus the acquisition of the master station signal is performed easily and surely even in a region wherein S/N is bad. |