精密单点定位结果转换至CGCS2000坐标方法

Methods of transforming precise point positioning results to CGCS2000 coordinates

为了解决精密单点定位结果存在坐标框架历元不明确、时间坐标基准不统一、使用速度场转换精度,导致难以应用到实际工程中的问题,分别采用全域七参数转换法、局域七参数转换法,以及使用点位速度进行转换的基线法、反距离加权法、欧拉矢量法对上海区域利用精密单点定位结果转换至CGCS2000坐标进行研究,并分析了其适用性。结果表明七参数方法精度略高于使用速度进行转换的方法,转换精度达到毫米级,可以满足实际工程中的需要,且局域七参数转换法精度略高于全域七参数转换法。使用速度进行转换的方法中基线法的转换精度最高,可以达到毫米级。在实际工程应用中推荐使用七参数转换方法将精密单点定位结果转换到CGCS2000坐标系下,以充分发挥精密单点定位技术的优势。

Precise point positioning results are difficult to apply to engineering because of unclear coordinate frame epoch,inconsistent time and coordinate datum,and low accuracy of velocity field conversion.To solve the problem,methods including global sevenparameter conversion method,local seven-parameter conversion method,baseline method using point velocity conversion,inverse distance weighting method,Euler vector method are tested with known coordinate point data in Shanghai.The results show that the accuracy of the seven-parameter conversion method is slightly higher than that of the velocity conversion method,and the conversion accuracy reaches the millimeter level,which can meet the needs of practical engineering,and the accuracy of the local seven-parameter conversion method is slightly higher than that of the global seven-parameter conversion method.Among the conversion methods using the velocity field,the baseline method has the highest conversion accuracy,which can reach the millimeter level.In practical application of engineering,the seven-parameter conversion method is recommended to convert the precision single-point positioning results to CGCS2000,so as to make full use to the advantages of precision single-point positioning technology.