Study on Slope Effect Modeling and Overlap Rate Control Method for Multibeam Bathymetry Coverage Width

Multibeam bathymetry technology overcomes the limitations of single-beam systems by enabling full-coverage depth measurements across wide swaths perpendicular to survey lines, even in relatively flat seabed areas. This study investigates the variation in multibeam coverage width under different seabed slope conditions and addresses the challenge of controlling overlap rates between adjacent swaths. Based on principles of geometric similarity and angular relationships, a mathematical model is developed to describe coverage width while accounting for the influence of the angle between the horizontal projection of the seabed slope normal vector and the survey heading. The effects of seabed slope on overall coverage performance are further analyzed. Using a case study of a rectangular survey area with a central depth of 110 meters, a slope of 1.5°, and dimensions of 2 nautical miles (north-south) by 4 nautical miles (east-west), the research identifies optimal parallel survey line spacing that satisfies the minimum overlap rate requirement. A genetic algorithm optimization model is employed to iteratively search for the most efficient measurement path, ultimately determining a minimum effective survey line length of 68 nautical miles. The results provide both theoretical and practical insights for route planning and operational efficiency optimization in multibeam bathymetric surveys.