| 摘要 |
PURPOSE:To enable outputting present position data even when only two dimensional measurement is possible, by calculating according to the GPS measurement data output for two dimensional position measurement based on this and a relative elevation data. CONSTITUTION:A GPS receiver 11 receives a wave from the GPS satellite and outputs a GPS measurement data DG including latitude, longitude and height. A barometric height meter 13 outputs a relative height data Z2 corresponding to the height difference between the present position and a standard position. A controller 14 having a present position data output part 15 outputs the present position data based on the data DG when the receiver 11 can do three dimensional measurement. If only two dimensional measurement is possible, the present position data DPOS is outputted by obtaining the absolute height data based on that data and data Z2. The controller 14 matches this a map data M read out of a CD-ROM drive 16, and indicates the self-car position on a display 17. |
