Application Research Of Integrated Navigation Ship Posture Correction In Multi-beam Sounding

When using the multi-beam bathymetric system for underwater terrain measurement,the measurement ship is inevitably affected by wind,waves and other factors,causing the transducer to produce rolling,pitching and vertical heave motions,which makes the multi-beam sounding Deep values produce errors.By studying the effect of hull attitude measurement error on the reduction accuracy of multi-beam footprints,it is of guiding significance for improving the accuracy of multi-beam sounding in field surveys.The Global Positioning System and Strapdown Inertial Navigation System combined system can take advantage of the shortcomings,the SINS/GPS integrated navigation system can output high-frequency,high-precision hull Position and attitude information.In this paper,the impact of hull attitude on the multibeam footprint reduction is taken as the starting point,and the research is focused on the positioning,attitude measurement and heave resolution of the SINS/GPS combined system.The main content of the paper is as follows:(1)The working principle of multi-beam sounding is introduced.Based on the beam footprint reduction equation,the ship's roll angle,pitch angle,heading angle and transducer heave and their measurement errors on the beam footprint are analyzed in detail The effect of reduction.(2)Based on the navigation principle of SINS,the problem of hull positioning and attitude measurement based on SINS is studied,and the pure inertial navigation solution is carried out through the measured data.The results verify that SINS has high shortterm accuracy,but the error accumulates with navigation time Characteristics.(3)Aiming at the problem of positioning and attitude measurement of the surveying ship,two solution models based on SINS/GPS,loose and tight combination,are studied,and the principles and characteristics of the two combination models are analyzed.On the basis of the Kalman filter model of the loose combination mode,the GPS dual antenna heading angle solution value is added to the measurement equation to form the SINS/GPS incomplete combination heading angle solution model.Through the design program,the measured data of GPS dual-antenna heading angle,loose combination,tight combination and incomplete combination were solved,and the results were compared and analyzed.(4)For the heave motion problem of the transducer,SINS high-pass filtering and GPS RTK assisted SINS two heave solution methods are used.The SINS high-pass filter solution method is based on the vertical motion characteristics of the transducer and processes the heave signal by designing an appropriate IIR high-pass filter.The GPS RTK assisted SINS transducer heave solution is based on the reliable characteristics of the SINS signal short-cycle reliable RTK elevation signal and longterm credibility,to achieve the fusion of the two signals.Combined with the measured data,the above two algorithms are analyzed and verified.The research results show that the attitude of the ship has an important influence on the accuracy of the multi-beam sounding.The accurate determination of the position and attitude parameters of the hull can accurately compensate the multi-beam sounding value,thereby ensuring the accuracy of the multi-beam sounding under adverse measurement conditions.