| 摘要 |
PURPOSE: To improve the azimuth accuracy of a navigation device for vehicle by using an estimated azimuth error calculated from the arrangement of GPS satellites and moving speed of a vehicle based on the present location of the vehicle. CONSTITUTION: A GPD receiver receives signals from GPS satellites and a satellite location information calculating section 215 which is provided as a satellite location detecting means detects the arrangement of the satellites from which the signals are received from the locations of the satellites, and then, a car speed calculating section 216 which is provided as a moving speed detecting means calculates the running speed of its own vehicle. In addition, an estimated azimuth error calculating section 219 which is provided as an azimuth error estimating means calculates an estimated azimuth error based on a function found from an empirically obtained relation between the then arrangement of the satellites and the running speed of the vehicle or a table indicating the relation. Then a discriminating means discriminates whether or not the azimuth calculated by an azimuth calculating section 218 provided as an advancing azimuth calculating means based on the estimated azimuth error is to be adopted. |
