| 摘要 |
PROBLEM TO BE SOLVED: To provide a car navigation system capable of improving the use efficiency of a GPS regardless of the presence or absence of SA operation. SOLUTION: A deviation computing unit finds and stores a difference between an own vehicle position estimation result based on map matching and a GPS positioning solution so as to find a mean value. According to the comparison between the mean value calculated by the deviation computing unit and a predetermined value, existence/absence of SA operation is determined, and according to the existence/absence of the SA operation determined in this process, UERE is switched and 2 drms is computed so as to be used as an error estimation value to the GPS positioning solution. Because the existence/absence of the SA operation is reflected on the error estimation value of the GPS positioning, solution, the GPS use efficiency can be improved. |
