一种线面组合的水下地形匹配算法

A Line-surface Integrated Algorithm for Underwater Terrain Matching

针对当前面匹配算法中采用Hu矩描述海底地形特征时存在细节辨识能力差而导致定位精度较低等问题,提出了一种线面组合的水下地形匹配算法。首先,引入经典TERCOM算法作为线匹配算法,改进其相似性度量方法和匹配区的搜索策略;然后,构造一种基于几何相似性的面匹配算子,用于在地形基准图中选取实测地形模型面的最优匹配;最后,设计一种基于固定阈值的线面算子的组合策略,实现水下地形匹配定位。试验结果表明,相比基于Hu矩的地形匹配算法,本文所提线面组合算法的定位精度明显提高,且稳健性更强。

The current underwater terrain surface matching algorithm,which uses Hu moment as similarity index,cannot gain fairly precious location due to its disadvantage in detecting slight difference.To solve this problem,a line-surface integrated terrain matching algorithm is presented.Firstly,the similarity evaluation method of traditional terrain contour matching(TERCOM)algorithm is improved,and strategy used to select the matching regions is developed.Then,a surface matching algorithm based on geometric similarity is established to find the optimum matching of real terrain.Finally,an integration means of the“line matching algorithm”and“surface matching algorithm”based on fixed threshold is proposed.Experimental results show that the proposed algorithm can obtain much higher location precision and better robustness than the surface underwater matching algorithm based on Hu moment.