Method for generating 3D seafloor terrain

3D Seafloor Mapping Technology Using Data Registration of Multibeam and Profiling Sonars

This technology reconstructs 3D seafloor terrain by cross-matching horizontal profile data acquired from multibeam sonar with vertical profile data from profiling sonar based on threshold points, and extracting feature lines using a weighted RANSAC algorithm.

Underwater optical camera use is limited, necessitating the use of sonar. However, 2D sonar images often suffer from lost height information, object distortion based on viewing angles, and low signal-to-noise ratios, making accurate seafloor reconstruction difficult.

This technology proposes a method to correct for lost height information by reflecting the difference in ultrasonic scanning angles between sonars to cross-calibrate and register horizontal and vertical profile data. It enables the acquisition of precise 3D terrain maps using only sonar, with applications in seafloor surveys, offshore plant design, and underwater tunnel construction.

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Key Features:

• Acquiring horizontal profile data using multibeam sonar and vertical profile data of the same terrain using profiling sonar
• Extracting feature lines for both multibeam and profiling sonar data using vertical cross-section profiles
• Cross-matching corresponding points between the two profiles using threshold points where the detection target exits the sonar's detection range
• Grouping points representing the seafloor and objects through clustering and determining a linear model connecting the two points

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This invention was developed with support from the Smart Underwater Tunnel System Research Center of the Ministry of Science and ICT.