Geomagnetic/inertial navigation integrated matching navigation method

The accuracy of an a priori geomagnetic reference map is a significant constraint on the geomagnetic matching navigation method. Especially when the aircraft enters an unknown environment, it is impossible to accomplish the navigation task using traditional geomagnetic navigation methods. Therefore, a geomagnetic/INS integrated matching navigation algorithm for long-scale navigation is proposed in this paper, which can perform navigation tasks regardless of whether there is an a priori geomagnetic map. This method combines a magnetogram-based matching navigation method with a geomagnetic bionic navigation method that does not require a geomagnetic map. The navigation trajectory is first analyzed in the area where the geomagnetic map is available, and the matching results are further corrected by filters for the inertial navigation system. Furthermore, when the aircraft flies through an unknown area without the a priori geomagnetic map, the nonmagnetic map navigation method is used to guide the aircraft to the destination. Finally, simulations are performed for the geomagnetic map distribution and noise effects that may occur during actual flight, and the obtained results show the effectiveness of the proposed algorithm in a complicated geomagnetic environment.