重力匹配导航的影响模式分析

摘要

从重力场匹配导航的改进TERCOM算法入手,针对采样长度、采样间隔以及重力测量误差对匹配结果的影响进行了系统分析,并在此基础上利用海洋年度重力测量数据设计了准实时仿真试验,结果表明:(1)采样长度对匹配结果有重要的影响,采样长度与重力基准图的分辨率比值在10～20之间时,能够获得较好的匹配效果;(2)适当增加采样间隔可以在一定程度上提高匹配的整体精度,但增加了匹配失效的风险,实际应用中采样间隔以2～4 min为宜；(3)重力测量白噪声误差对匹配结果影响相对较大,过大的误差将不能得到有效匹配,水下重力测量误差最好能控制在2 mGal以内.%The effect of sample length, sampling interval and gravity measurement error on the gravity aided navigation is systematically analyzed based on modified TERCOM (terrain contour matching) arithmetic. The quasi-real-time simulation shows that: (1) The sample length has much influence on the matching result, too long or too short can neither match to the optical grid point. Experiments show that the matching result is good when the ratio of sampling length to the base map resolution is between 10 and 20; (2) Increasing the sampling interval can improve the matching precision when sample length is fixed. However the risk of matching error increases at the same time. The sampling interval is chosen to be 2 min to 4 min is recommended; (3) The white noise error of gravity measurement has much influence on the matching, and too much measurement error coould induce invalid matching. Measurement error within 2 mGal is recommended.