水下地形辅助导航适宜地图分辨率的选取

Selection of Digital Map Resolution for Underwater Terrain Aided Navigation

针对目前水下地形辅助导航用数字地图分辨率选取不明而制约导航性能发挥的问题,根据某海域真实水深数据建立了水下地形数字高程模型;借鉴误差传递思想,基于递推贝叶斯理论和质点滤波理论,对小起伏和大起伏2种典型地形区分别从解析和仿真角度给出了地形辅助导航用适宜的地图分辨率;然后,基于地形轮廓匹配(TERCOM)算法对不同地形下数字地图分辨率与匹配误差的定量关系进行了多项式回归分析,进一步确定了适宜的地图分辨率。结果表明,解析分析结果与数值仿真结果大致相当,相互佐证了研究结果的合理性;不同地形匹配区对适宜分辨率的要求不同,小起伏区和大起伏区适宜地图分辨率参考范围大致分别在13 m和25 m左右,大起伏区对地图分辨率的要求较小起伏区低;数字地图分辨率与匹配误差关系近似服从多次曲线变化规律。研究成果可为水下地形辅助导航中数字地图制作、分辨率选取及水下测量工作提供相关参考。

Aiming at the problem that the selected digital map resolution for navigation is not clear,which restricts navigation performance,an underwater digital elevation model of underwater terrain was built based on the real water depth data of the certain sea area.According to the idea of error transfer,the recursive Bayesian theory and the point mass filter theory,appropriate digital map resolution for terrain aided navigation was given via analysis and simulation for the two typical areas with small fluctuation and large fluctuation.Then,based on the terrain contour matching(TERCOM)algorithm,the polynomial regression analysis of the quantitative relationship between digital map resolution and matching error was carried out for different terrain to further determine the appropriate map resolution.The results show that the analysis results are approximately equivalent to the simulation results,which proves the reliability of the research results.The appropriate resolution ranges for small and large fluctuation areas are around 13 m and 25 m,respectively.Diverse characteristic terrains need different appropriate resolution,and large fluctuation area requires lower digital map resolution compared with small fluctuation area.The relationship between the digital map resolution of different terrain and the matching error appropriately obeys the change law of polynomial curve.This research may provide reference for making of digital map,resolution selection,and underwater measurement in underwater terrain aided navigation.