水下地形匹配等值线算法研究

Iterative Closest Contour Point for Underwater Terrain-Aided Navigation

文[1]将图像配准中使用的等值线算法引入到水下地形匹配中,文[2]全面验证该算法的有效性。但是,仿真结果表明,该算法在初始误差较大时(如2海里)容易发散,这是由于目前的研究都认为匹配起始点是精确已知的,而实际中却很难满足该条件。本文提出了将匹配起始点引入匹配过程和进行粗匹配等两点改进措施,仿真结果表明,这两个改进措施是有效的,特别是当INS精度较低时,相比较于TERCOM算法,其匹配过程更为平稳,匹配精度也更高。

Behzad （1999） introduced iterative elosest contour point （ICCP） from image registration to underwater terrain matching and provided its exact equations and proved its validity with an example. Bishop （2002） proved its validity extensively. However, it was assumed in their research that the matching origin was known exactly while it was seldom satisfied in practice. Simulation results indicated that ICCP diverged easily when the initial INS error was very large （such as 2 nautical miles）. Two enhancements, adding the matching origin into matching process and the coarse matching, were put forward to resolve the problem. Simulation results showed that the updated ICCP matches application conditions very well and converges with very high precision. Especially, when INS precision is not high, the updated ICCP matching process is more stable and its precision is higher than TERCOM＇s.