对Proj.4库中用于坐标系统转换的赫尔默特模型进行了修正,结合GDAL库的相关函数,实现了矢量数据及栅格数据的坐标系统转换。对于栅格数据的国家2000坐标系到1954年北京坐标系及1980西安坐标系的转换,由于栅格数据不具有空间直角坐标,不能按照矢量数据的转换方法进行,为此对七参数的求取进行了修正。精度评定表明,该方法及程序能够实现矢量及栅格数据的坐标系统转换。

This paper modified the Helmet model which transforming coordinate system in Proj.4 library. Combined with related function of GDAL library, the paper realized the transformation of coordinate system of vector data and raster data. For raster data of CGCS2000 coordinate system transform to the Beijing Geodetic Coordinate System 1954 and Xi'an Geodetic Coordinate System 1980, raster data does not have the spatial rectangular coordinate, cannot be carried out in accordance with the conversion of vector data method. According to these, this article modifi ed the seven parameters. Through the precision evaluation, the results show that the method and the program can coordinate system conversion meet below GPS C grade control level of vector and raster data.