Suitable Matching Area Selection Algorithm Based on Terrain Triangulation Model for Terrain-Aided Inertial Navigation

The terrain suitable matching area (SMA) selection algorithm is one of the key technologies for underwater terrain-aided inertial navigation to achieve good navigation and positioning results. Within the SMA, the accuracy of positioning and the matching rate of the terrain matching algorithm can be improved. Traditional threshold selection algorithms usually use statistical information on various features of the terrain field as evaluation indicators. However, these methods are difficult to reflect the spatial information of underwater terrain, while misclassification often occurs in the selection process. This article proposes an SMA selection algorithm for the underwater terrain-aided inertial navigation based on terrain triangulation, which converts the digital terrain map (DTM) from a raster map to terrain triangulation model. This is a novel approach that extracts eight types of spatial features from a triangulation model to analyze the characteristics of terrain. The Gaussian mixture model (GMM) clustering method is used to automatically select and divide the SMA based on the feature parameter matrix. Simulation shows that the proposed algorithm can achieve three-class classification of the terrain field and the select more suitable-matching area, which totally cover the result of traditional and other mainstream algorithm. Marine experiment verified the proposed algorithm.