| 摘要 |
PURPOSE:To enable selection of an optimum satellite whereby an error is reduced to the minimum, by comparing the present places of a moving body which are calculated from a distance of the moving body from a GPS satellite and position data from a road-side antenna. CONSTITUTION:This apparatus redraws a displayed map on a display screen sequentially with a change of the present place and synthesizes and displays the present place on the displayed map. On the occasion, a satellite navigation means 31 receives a radio wave emitted from a GPS satellite, calculates a distance between the GPS satellite and the present place and calculates the present place of a moving body. Meanwhile, a road-side position information receiving means 33 receives position data transmitted from a road-side antenna disposed at a predetermined prescribed position in a road traffic system and calculates the present place of the moving body. An optimum satellite selecting means 35 compares positional informations from the means 31 and 33 with each other and selects an optimum satellite in the means 31. |
