Acta Geodaetica et Cartographica Sinica ›› 2024, Vol. 53 ›› Issue (12): 2338-2348.doi: 10.11947/j.AGCS.2024.20230549

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Scale-adaptive Mercator projection plane geodesic precise plotting algorithm

Tian XIE1(), Jian DONG1(), Lulu TANG1, Mengkai MA1, Mingyang ZHANG2, Zikang SONG3, Dong WANG1   

  1. 1.Department of Military Oceanography and Surveying, Dalian Naval Academy, Dalian 116018, China
    2.Troops 31457, Shenyang 110079, China
    3.Chart Information Center, Tianjin 300450, China
  • Received:2023-12-13 Online:2025-01-06 Published:2025-11-06
  • Contact: Jian DONG E-mail:xietian0229@163.com;navydj@163.com
  • About author:XIE Tian (2000—), male, postgraduate, majors in geographic information methods and maritime delimitation. E-mail: xietian0229@163.com
  • Supported by:
    The National Natural Science Foundation of China(42071439)

Abstract:

Addressing the issues of mismatched data volume and mapping precision in the current Mercator projection plane geodesic line plotting methods, as well as the excessive arch height errors in equator-crossing geodesic line plotting, this paper, based on the analysis of the geometric characteristics of geodesic line projection curve on the Mercator projection plane, drawing on the idea of binary search, establishes a model for precise calculation of the equatorial division points of geodesic lines, achieving the resolution of these points under any given scale for equator-crossing geodesic lines. By analyzing the changing relationship between the tangent azimuth angles of interpolation points and the arch apex, the study constructs a set of search rules for the apex, guided by precise geodetic azimuth angles, thus facilitating rapid calculation of arch height errors for any segment of the projection curve on the Mercator projection plane. Drawing analogy with the Douglas-Peucker algorithm concept, the study adopts permissible cartographic error as threshold for curve simplification, ultimately enabling rapid and precise plotting of geodesic lines at any given scale. Experimental results demonstrate that this algorithm significantly improves computational efficiency and reduces interpolation redundancy. In typical application scenarios, under the strict control of limiting arch height error to not exceed permissible cartographic error, the maximum reduction in the number of interpolation points obtained by this algorithm can reach approximately one-thousandth of existing algorithms, and the computation time can be reduced to approximately one-hundredth.

Key words: geodesic line plotting, Mercator projection, binary search, Douglas-Peucker algorithm, geodesic theme calculation

CLC Number: