Design And Implementation Of Multibeam Sounding Data Postprocessing Software Based On QT

As one of the important components of the multibeam sounding sonar system,the postprocessing software of multibeam sounding data plays a crucial role in the accurate output of the operational results such as the digital bathymetric map and the backscattering image of the seabed.This paper mainly focuses on the postprocessing process of multibeam sounding data and the key technical issues in the processing process,and researches from five aspects:beam footprint homing solution of sounding data,acoustic tracking algorithm,detection and elimination of outliers of sounding data,self-calibration method of multibeam sounding sonar transducer array installation deviation,and development of postprocessing software of multibeam sounding data.The main contents are as follows:Firstly,based on the postprocessing process of multibeam sounding data,the acoustic line tracking method based on the assumption of intra-layer constant sound velocity is studied.At the same time,the homing method of beam footprint is studied.The spatial position of the beam footprint in the hull coordinate system is calculated through the oblique distance,beam Angle and auxiliary sensor information.On this basis,the method of detecting and eliminating outliers of multibeam sounding data is studied,and the filtering performance and limitations of median filtering and trend surface filtering,two commonly used depth data filtering methods,are compared and analyzed in combination with the actual sounding data onto the lake.Secondly,the self-calibration method of multibeam sonar array installation deviation is studied.According to the depth data obtained after the above preprocessing,when the spatial homing is completed,the installation deviation from sonar array of roll,pitch and yaw is calibrated based on the statistical deviation of sounding data between calibration lines,combined with the spatial distribution characteristics of underwater terrain within the measurement range of calibration lines.On this basis,combined with the test data onto the lake and the Hypack multibeam sounding data postprocessing software,the performance of the calibration module of the software in this paper is compared and analyzed.The test results show that the software module achieves the expected effect.Finally,the design and implementation of multibeam sounding data postprocessing software is carried out.Combined with the data postprocessing technology and methods studied above,QT is used as the development environment to realize the design functions of multibeam sounding data reading and display,coordinate homing,acoustic line correction,beam footprint homing and solving,outlier detection and elimination,self-calibration of installation deviation,3D display of submarine topography,etc,and carry out functional testing for each module of the software combined with the test data onto lake and sea.The verification process covers the key technical issues involved in the postprocessing process of multibeam sounding data,achieves the expected design objectives of the software function,and orderly completes the postprocessing work of the whole multibeam sounding data.