基于惯导误差的多波束测深精度分析

Precision analysis of multi-beam bathymetric system based on INS error

在远海水域海底地形测量中,为了减小波浪引起的船体姿态变化而导致多波束测深系统在垂直深度和平面位置产生的误差,通常以低成本的INS/GPS组合惯导设备辅助多波束测深系统以提高测量精度。考虑以多波束测深系统中惯导误差源为研究对象,根据测深坐标系的关系讨论了多波束测深系统误差因素,结合惯性导航系统特点考虑了影响测量精度的主要误差源,重点分析加速度计零偏及安装误差与测深误差的关系,建立了其误差源与多波束测深精度之间的模型,仿真比较了惯性导航系统主要误差源对于水深测量精度的影响,其结果表明2×10-4g加表零偏对测深精度的综合影响不大于测量深度的0.23%。

Low-cost INS/GPS integration system is usually used to improve the surveying accuracy of multi-beam bathymetric system in open sea in order to reduce the wave-caused ship deformation error of multi-beam bathymetric system in vertical depth and planimetric position. In this paper, the INS errors of multi-beam bathymetric system are analyzed, and the error factors of multi-beam bathymetric system are discussed based on the relation to sounding coordinate system. The main errors affecting the measuring accuracy are considered in combination with the characteristics of INS. The accelerometer bias and installation error are analyzed, and the relation model between error sources and the accuracies of multi-beam bathymetric system for the correspondence is built. The simulation results demonstrate the effect of the main INS errors on the accuracy of bathymetric survey. It is concluded that the error of surveying depth caused by accelerometer bias of 2×10-4g is no more than 0.23%.