Adaptive Point Mass Filter and Its Application in Terrain Matching Navigation

Terrain matching algorithm is the core part of terrain-aided inertial navigation system (INS), and point mass filter (PMF) is often used as a terrain matching algorithm. In PMF, the construction method and calculation amount of the point mass set are important parts which affect the accuracy. To comprehensively consider the construction of point mass set and calculation amount, this article proposes an adaptive construction method of point mass set based on probability distribution. According to the characteristics of the probability distribution to be approximated, the method transforms the preset point mass set to obtain point mass set of the current moment. Aiming at the problem of calculation error, which is caused by the process noise intensity being smaller than the resolution of the point mass set, a local convolution method is proposed in this article, in which the convolution result is obtained by subdividing the local area near the point mass set. Finally, the framework of the proposed adaptive PMF (APMF) in terrain matching is given. Numerical simulations show the superiority of the proposed APMF, and the experiment shows the effectiveness of the proposed method in terrain-aided INS.