| 摘要 |
PURPOSE:To enable a cause when no position cannot be measured to be judged positively by detecting a failure in an antenna along with a deterioration coefficient and an electric field strength based on electric wave of an artificial satellite. CONSTITUTION:A position-measuring means 13 utilizing a satellite measures current position, altitude, speed, and azimuth of a traveling object based on an electric wave of an artificial satellite which an antenna portion 1 receives. A reception portion 4 of the current position recognition means recognizes this based on this data and an antenna failure detection portion 12 which is provided here measures electric wave and judges according to a specified range, thus enabling a failure of the antenna portion 1 to be detected. Also, a reception state detection means 18 which is connected to the means 13 detects a deterioration coefficient which indicates deterioration of position-measurement accuracy of the means 13 and electric field strength. The deterioration coefficient is obtained from a position data of the artificial satellite which is used at the time of measurement of position and the electric field strength is detected by the strength of received electric wave. When this data is outside a specified range, a prohibition means 19 prohibits recognition of the current position of the traveling object based on data of the means 13, switches to other means, and eliminates reception disable according to state of the artificial satellite. |
