| Multibeam bathymetric system, also named swath sounding system, is a large-scale combination equipment which is used for under-water terrain mapping. It's a complex system with various kinds of high techniques, and it needs to gather correlative information data. There are many kinds of errors and environment interferes while collecting the data. In multibeam bathymetry data processing, it is the main task to choose suitable methods, in order to eliminate errors,get an exact measuring result, and enhance the quality of the digital chart.In this paper some key technology of multibeam bathymetric data processing are studied. Firstly, various formats of raw multibeam data are analyzed, and the method about raw multibeam data extraction is given. Next, swath aided parameter pre-treatment is studied based on the analyzing of the main sources error of the system, including sound velocity profile correcting technique, tide correcting technique, positioning data error determination and fitting, and attitude data processing. Then, the sources and types of effect factors for depth are analized. And from the characteristic of multibeam bathymetric data, the trend-surface filter and the iterative weighted filter based on M robust estimate are used to detect and eliminate gross errors of multibeam data. Finally, the interpolation and smooth methods are applied to process multibeam data, and the multibeam data is merged to obtain the (x, y, z) information of the geodetic coordinates.Based on the theoretical research above, the multibeam bathymetric data pre-treatment software is designed and completed using Microsoft Visual C++6.0. The main function of the software is to eliminate gross and random errors, to compensate system errors caused by attitude data and positioning data, to merge location and depth information to obtain the geodetic coordinates, and to generate high-precision 3D seafloor sampling data. The software provides a basis for building digital terrain model in the future. |
PDF Full Text Request