摘要 |
PURPOSE:To simply and quickly search and confirm own present location by displaying the page number of a map book which contains the map in the vicinity of the own present location and simultaneously displaying own current tracks on the display device. CONSTITUTION:Each of the accurate time signal navigational radio waves transmitted from the global positioning system(GPS) satellites 4, 4...n is received by a GPS receiver 6. A signal processing means 7 obtains each of the arrival time of the navigational radio wave time signals, computes the distances between each of the GPS satellites 4 and own vehicle's location and fixes own present location. Then, a CPU 3 reads all page numbers of a map book from a map information storage section 8, successively reads the reference point of each page and extracts the page number of the map book in which the present location map is contained. Furthermore, the CPU 3 displays the page number and the latitude and the longitude of the present location on a display screen and also displays the tracks of the present location at the corresponding location on the display screen of the display device 9. |