提高城市大比例尺地形图转换到CGCS2000精度的探讨

Method for Improving the City Large Scale Topographic Maps Coordinate Transformation Accuracy between the City Coordinate System and CGCS 2000

针对在进行城市坐标系中的大比例尺地形图转换到CGCS2000中,采用统一区域坐标转换模型进行整体转换,将会使地形图在转换后的精度不能满足成图精度要求,提出了通过对区域内的所有控制点进行兼容性检测,剔除不能满足精度要求的点后,对所有控制点构建TIN,然后采用仿射变换模型分块对各三角形内的大比例尺地形图进行转换,从而实现提高局部转换精度,并用实例进行验证,结果表明,此方法可行,能得到满足精度要求的转换成果。

For the purpose of translating the urban coordinate system to the CGCS2000 for large-scale topographic maps,the integral transformation productions using an uniform transformation model and parameters don't satisfy the accuracy.A method was put forward to solve the accuracy problem in the article.First,compatible analysis was made for all control points and gross error points were get rid of.Then remaining control points were build TIN and calculated partitioned transformation parameters.As a result,we could improve the partitioned transform accuracy.Last,a real example was used to testing.The result shows that method put forward in the thesis is feasible and can enhance the transform accuracy.