基于GNSS方位辅助惯性导航系统的水下地形精密测量技术

多波束测深技术是目前水下地形测量的主要技术手段,测量平台的瞬时姿态及方位是影响多波束测深系统最终成果准确度的重要因素。GNSS方位辅助惯性导航系统,作为目前应用较为广泛的方位、姿态、及位置综合测量系统,不仅能够提供高精度位置信息,同时也能提供测量平台的瞬时姿态及方位数据,而且因为具有GNSS方位辅助测量,使得最终方位测量结果比传统方位测量精度大大提高,这对于多波束最终测量成果精度提高具有重要意义。文中从GNSS方位辅助惯性导航系统原理及技术优势出发,结合Trimble RTX后处理技术,从姿态测量、方位测量及辅助高程测量方面分析了在多波束水下地形测量中的应用,并以实际测量成果来展现其在水下地形精密测量技术方面的优势,结果显示,定位精度可以达到优于2 cm级别,方位精度可以优于0.01°(依赖于双GNSS天线之间的基线长度),该技术对水下地形测量准确度提升作用显著。

Underwater Terrain Precision Measurement Technology Based on GNSS Azimuth Aided Inertial Navigation System

Multi-beam bathymetry is the main technique in underwater topography measurement. The instantaneous attitude and heading of the measuring platform are the important factors affecting the accuracy of the final results of multi-beam bathymetric system. GNSS heading-aided inertial navigation system is a comprehensive measurement system for heading, attitude and position and widely used at present. It can provide not only high-precision position information, but also instantaneous attitude and heading of the measuring platform. Thanks to the GNSS heading-aided measurement, the final heading accuracy is greatly improved compared with traditional heading measurement. It is of great importance to improve the accuracy of the final measurement results of multi-beam. Based on the principle and technical advantages of GNSS Heading Aided Inertial Navigation System and Trimble RTX post-processing technology, the application of GNSS Heading Aided Inertial Navigation System in multi-beam underwater topographic survey is analyzed in attitude measurement, heading measurement and auxiliary height measurement. The advantages of GNSS Heading Aided Inertial Navigation System in precise underwater topographic measurement technology is shown. The results shows that the positioning accuracy is better than 2 cm, and the heading accuracy can be better than 0.01 degrees (depending on the baseline length between two GNSS antennas). This technology can significantly improve the accuracy of underwater topographic survey.