Modeling and Solving of Seafloor Terrain Detection Based on Multibeam Bathymetry

Multibeam bathymetry, as an advanced method of ocean topographic sounding with higher measurement accuracy and efficiency, is able to overcome the limitations of traditional methods and offers new possibilities for research and application in the field of marine science and engineering. The development of this technology will further promote the accuracy and comprehensiveness of marine topographic exploration and provide strong support for the development and application of marine-related fields. In this paper, the coverage width W of the strip is first defined as the spacing between the intersection points of the two beams at the edge of the strip and the seafloor surface multiplied by the slope cosine value. Any position is taken, and the mathematical model of the coverage width W is deduced by plane geometry based on the water depth D, the transducer opening angle θ, and the slope a at this time. Finally, according to the established model of overlap rate and coverage width, and the formula for calculating the seabed depth, the water depth of 64.76m, coverage width of 224.81m, and the overlap rate with the previous line of 14 % are obtained at +200m from the center point. Then, the spatial coordinate system was established, and the analytical equation of the associated slope and the analytical equation of the cone formed by the bathymetric beam were obtained to acquire the analytical equation of the ellipse formed by the oblique intercept cone of the seafloor slope. Then solve the analytical equation of the survey line projection in the spatial coordinate system. Then a plane rectangular coordinate system on the slope surface is established, and the ellipse and the analytical equation of the projection are transformed into space rectangular, which coordinates to obtain the analytical equation of the two in the plane. A calculation results in a coverage width of 451.43 when the distance of the survey vessel from the center of the sea is 0.3 nautical miles and the angle of the direction of the survey line is 45.