| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that it is difficult to specify whether the abnormality generated in a measuring position calculation result is caused by the external factor of a GPS receiver such as a GPS satellite state or the like, or the factor of the GPS receiver itself such as a state such that the radio wave from a GPS satellite can be normally received but cannot be demodulated or the like, because a detection circuit cannot be diagnosed at the time of self-diagnosis in the conventional GPS receiver. SOLUTION: The output signals of the false noise generators 11-13 and frequency generators 19-21 of the receiving circuits 37-39 among a plurality of the receiving circuits 36-39 constituting the GPS receiver are inputted to the other receiving circuit 36 as inspection signals at the time of self-diagnosis to be processed, and the processed result is judged to be accepted or rejected. When there is abnormality in the measuring position calculation result, it can be specified whether the abnormality is caused by the external factor of the GPS receiver such as a GPS satellite state or the like, or the factor of the GPS receiver itself such as a state such that the radio wave from the GPS receiver can be normally received but can not be demodulated or the like. |
