Acta Geodaetica et Cartographica Sinica ›› 2025, Vol. 54 ›› Issue (8): 1439-1451.doi: 10.11947/j.AGCS.2025.20240458

• Marine Survey • Previous Articles     Next Articles

Hierarchical encryption matching algorithm for adjacent strip splicing in airborne LiDAR bathymetry

Dongdong PU1,2(), Hongzhou CHAI1(), Yongzhong OUYANG3, Chao DONG2,4   

  1. 1.Institute of Geospatial Information, Information Engineering University, Zhengzhou 450001, China
    2.Key Laboratory of Marine Environmental Survey Technology and Application, Ministry of Natural Resources of the People's Republic of China, Guangzhou 510300, China
    3.School of Smart Marine and Technology, Fujian University of Technology, Fuzhou, 350118, China
    4.South China Sea Marine Survey Center, Ministry of Natural Resources of the People's Republic of China, Guangzhou 510300, China
  • Received:2024-11-11 Revised:2025-05-14 Online:2025-09-16 Published:2025-09-16
  • Contact: Hongzhou CHAI E-mail:pudd2022@163.com;chaihz1969@163.com
  • About author:PU Dongdong (1993—), male, PhD candidate, majors in marine geodesy. E-mail: pudd2022@163.com
  • Supported by:
    The National Natural Science Foundation of China(42074014)

Abstract:

The complex system integration errors and the high dynamism of the marine environment pose numerous challenges for the adjacent strip splicing in airborne LiDAR Bathymetry (ALB). Existing methods primarily rely on spatial geometric features to establish correspondence, lacking thorough analysis and optimization of this correspondence. Potential outliers in the correspondence significantly impact the accuracy of spatial alignment. To address this, a hierarchical encryption matching algorithm for adjacent strip splicing in ALB is proposed. Our algorithm leverages the robustness of graph space and dynamic optimization mechanism to mitigate the effects of potential mismatches. Firstly, calculate the multi-scale features of ALB point cloud and select points with stable and significant features as feature points. Secondly, based on feature points, a global graph matching is constructed to facilitate the coarse alignment between adjacent strips. Then, an encrypted local graph model is constructed within the neighborhood of the globally matched nodes. Finally, a dynamic mechanism featuring one-to-many and bidirectional matching is employed to identify the optimal matching and eliminate outliers of correspondence. Our algorithm divides the process of adjacent ALB strips splicing into two levels: coarse alignment and fine registration. In the coarse alignment phase, the stability of the global graph structure is fully leveraged. For fine registration, a dynamic optimization strategy utilizing a local neighborhood encryption graph model is employed, effectively bolstering the robustness of correspondence by harnessing local information. The experiment employed measured point cloud data from three regions featuring different carriers and shapes. It compared the performance of RANSAC-ICP, 3D-NDT, MCM algorithms, and features matching algorithms for verification purposes. The accuracy was assessed using rotation error, translation error, and overall error. Balancing accuracy and efficiency, the results demonstrate that the algorithm proposed exhibits significant advantages.

Key words: airborne LiDAR bathymetry, strip splicing, hierarchical graph matching, dynamic optimization, correspondence

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