| 主权项 |
1. A system for estimating the position of a land vehicle, the system comprising:
a navigation filter that receives input from a GNSS receiver, a three-axis rate gyroscope, a three-axis accelerometer, and an elevation database; wherein, the elevation database stores elevation data and sends an elevation estimate to the navigation filter in response to a query from the filter, the query containing a lateral position for which an elevation estimate is sought; and, the navigation filter implements a Kalman filter to estimate position of the land vehicle based on GNSS data when GNSS signals are available and based on gyroscope, accelerometer and elevation database input when GNSS signals are not available. |
