Algorithm for geomagnetic navigation and its validity evaluation

Geomagnetic navigation is a new branch of the passive autonomous navigation technique. According to different processing methods for geomagnetic data, there are two ways to implement geomagnetic navigation, one is geomagnetic matching and the other geomagnetic filtering. The geomagnetic navigation system is intensively studied on the background of guidance and navigation for flight vehicle. The principle of geomagnetic matching and geomagnetic filtering is introduced. With employment of real data, the measurement equations are obtained by using surface Spline method. Using MAD (mean absolute difference) and EKF (extended Kalman filter), simulations are calculated separately. Simulation results show geomagnetic matching has high anti-interference ability and better validity under appropriate flight path. Using geomagnetic filtering can greatly improve the efficiency of navigation system when the initial state error and geomagnetic measurement noise are controlled in a certain range.