CGCS2000启用后,用于地形图图廓线和坐标网变换的高精度坐标转换格网模型的建立成为实用中的重要问题。本文阐述我国CGCS2000高精度坐标转换格网模型的建立方法。一是讨论坐标转换最小曲率方程,该方程同时具备整体光滑和局部光滑特性,可以更好地符合地图线状要素坐标转换时的连续光滑性;二是提出格网节点迭代计算方法以及拟舍推估两步极小法构建区域性格网模型的方法,构建了格网模型数据结构;三是给出全国范围CGCS2000高精度坐标转换格网模型的最优格网间距和转换精度,按48433个2000国家大地控制网点坐标构建了BJS54和XAS80到CGCS2000坐标转换格网模型,转换后的点位外符精度分别为0.26m和0.03m。
After implementing CGCS2000, the establishment of the high precise coordinate transformation grid model which is mainly used to transform sheet lines and coordinate grids of topographic map becomes important to be solved in the mapping application. The establishment method of the high precise coordinate transformation grid model of CGCS2000 is proposed. First, the minimum curvature equation of coordinate transformation is discussed. And it possesses both the whole and local smooth characteristics, so it can be better in keeping with consecutive smooth characteristics for the coordinate transformation of map's linear feature. Second, the iterative calculation method of grid nodes and the establishment method of regional grid model using the resolution of collocation by two minimization steps are advanced. The data structure of grid model is constructed. Third, the countrywide optimized grid interval and transformation precision of high precise coordinate transformation grid model of CGCS2000 are presented. The coordinate transformation grid models from BJS54 and XASS0 to the CGCS2000 have been constructed using 48 433 points of 2000 national geodetic control network of China, and the positioning external accuracy of both models are 0.26 m and 0.03 m respectively.