A Novel Terrain-Aided Navigation Algorithm Combined With the TERCOM Algorithm and Particle Filter

In order to overcome the shortcomings of the Beihang University of Aeronautical and Astronautics inertial terrain-aided navigation II (BITAN II) algorithm, which is based on extended Kalman filtering, a novel algorithm combined with the terrain contour matching (TERCOM) algorithm and particle filter is proposed. Compared with BITAN II, the proposed algorithm involves a new algorithm framework, acquisition mode, and mode control logic. In particular, the acquisition mode employs TERCOM to implement a consistency voting algorithm, which can quickly and accurately obtain an initial position given in a large initial position error; the mode control logic is designed using the instantaneous information of strapdown inertial navigation system, such that false fix can be effectively detected, and security and accuracy can be guaranteed as well. Experiments are carried out using the digital elevation model and real flight data, and show that, in comparison with BITAN II, the algorithm presented in this paper is reliable and achieves relatively high positioning accuracy in the case of large initial position errors and large altimeter measurement noises.