| 摘要 |
PURPOSE:To recognize in what extent from the display position a vehicle is by displaying variably according to present position detecting accuracy of the vehicle. CONSTITUTION:A storage means 12 stores necessary information for travel guidance including a map. Then, an electric wave from a satellite is received by a receiver 14a of a positioned measuring system (GPS) of a present place detection means 14 to detect the present position of the vehicle. The size of marking display of the present position in information of the travel guidance (the map of the present travel area, a target place to be guided and the present place calculated by means 14) displaying on a display means 10 by a control means 16 is made variable corresponding to degradation calculation (GDOP) of the GPS. In other words, the size (D) of the marking display is calculated by a prescribed formula from a scale of the map and the GDOP. Accordingly, in case the detecting accuracy of the present position by the GPS is satisfactory, a value of the GDOP is small and the size (D) of the marking display is made small and on the other hand, in case the detecting accuracy is made inferior, the value of the GDOP is large and the size (D) of the marking display is made large. In this way, the detecting accuracy of the means 14 can be visibly recognized simply and surely. |
