沿海区域不同坐标系统转换方法研究

沿海区域的测绘资料主要采用1954年北京坐标系、1980西安坐标系和2000国家坐标系(旧称WGS84坐标系),造成使用不便,需要构建这些系统之间的转换关系。不同方法和不同分区的大量试算表明,1980西安坐标系与WGS84坐标系可以采用7参数转换模型,3个分区和5个分区的精度都能达到0.5 m,其中5个分区的精度较好。由于1954年北京坐标系的特殊性,简单的7参数模型不能确保系统的转换精度,1954年北京坐标系与WGS84坐标系最好采用曲面拟合方法实现坐标转换,整个沿海区域采用6个分区,精度可以达到0.5 m以内的转换要求。

Methods for the Transformation of Different Coordinate Systems Applied in the Littoral of China

Three coordinate systems,namely Beijing coordinate system 1954/BJ1954,National Geodetic coordinate system/XI′AN1980 and China Geodetic Coordinate System 2000/CGCS2000(also called as WGS84),are currently applied in the littoral of China. However,these systems have caused a lot of inconvenience in the practical application. In addition,by means of the Helmert transformation model,usually called as 7-parameter model,the accuracy can not be guaranteed for the transformation of BJ1954. Therefore,it is necessary to determine the transformation relationship among these systems. For this purpose,a large number of tests were carried out by means of different methods and partitions. The results have indicated that the Helmert model can be applied for the transformation between XIAN 1980 and WGS84 and an accuracy up to 0.5 m can be reached for both 3-section and 5-section partitions,having a better accuracy for the 5-section partition. For the transformation between BJ1954 and WGS84,it is better to use the surface fitting method,by means of which a transformation accuracy within 0.5 m has been reached for a 6-section partition in the whole littoral of China.