ITRF 2008与ITRF 2014的差异对GNSS数据处理的影响

针对全球导航卫星系统(GNSS)数据处理过程中旧的ITRF 2008参考框架现势性不足及新的ITRF2014框架在数据的数量与质量、参数模型、测站的分布合理性上均有提高等状况,该文以陆态网的最近两年的观测数据为例,对比分析了ITRF2008和ITRF2014框架下各测站的坐标、基线长度、水平速度场的差异,以期为当前高精度GNSS数据处理提供参考。实验表明:两个框架下的成果经基准转换后,测站在X、Y、Z方向的差异均为毫米级;基线差异平均在1 mm以内;水平速度场差值的最大值为5.75(mm·a~(-1)),最小值为-4.88(mm·a~(-1)),平均值为-0.45(mm·a~(-1)),方向上差值的平均值为0.02rad。目前两个框架的差异对一般工程应用基本上可以忽略,但对地震监测的陆态网来说,则必须考虑。

The impact of differences between ITRF2008 and ITRF2014 on GNSS data processing

In view of the problem that the old reference frame is insufficient in GNSS data processing,the data and the quality,the parameter model and the distribution rationality of the new ITRF2014 are improved,this paper analyzed the differences of the coordinates,baseline length and horizontal velocity field of the stations under the framework of ITRF2008 and ITRF2014 in order to provide a reference for the current high precision GNSS data processing.The results showed that the differences in theX,Y andZ directions were in millimeters after transformation,the average of the baseline differences was within 1 mm;The maximum value of the horizontal velocity field was 5.75(mm·a-1),the minimum was-4.88(mm·a 1),the average was-0.45(mm·a-1),and the average of the difference in the direction was 0.02 rad.The differences in the reference frame were negligible for general engineering,but must be considered for CMONOC for seismic monitoring.