南极中山站数据处理中IGS框架站的选择

ON SELECTION OF FRAMEWORK STATIONS' FOR DATA PROCESSING OF ANTARCTIC ZHONGSHAN STATION

以计算中山站2007年第1天到第100天的数据为例,对计算南极GPS观测数据时如何选择IGS跟踪站作为框架基准站问题进行了探讨。在处理过程中,对IGS站的选取分为选站数量、网形、网缘、Z坐标南北半球互相抵偿性4种情况进行了计算,并对得出的结果从均方根残差NRMS、基线向量、基线重复率、坐标中误差4个方面进行了比较,得出以下结论:在进行南极大陆单点GPS数据处理时,为得到国际地球参考框架下准确的坐标,应加入5个均匀分布在未知点周围的IGS站参与计算,距离未知点较近的点为必选点,所选点应均在南半球,且不需要考虑南北半球Z坐标的抵偿问题。

Taking the calculation of the first hundred days＇ data of Zhongshan station with the help of GAMIT as an example,the principles for choosing IGS tracking stations as fiducial station in Antarctic GPS data processing are discussed. Aiming at choosing IGS stations, the net-shaped, net margin, number of selected stations and mutual offset of polar coordinates Z are respectively calculated, and the results are compared with each other in following aspects： NRMS, baseline vector, baseline repetition rate and mean square error of coordinate. In order to obtain accurate coordinate in International Terrestrial Reference Frame, the following conclusions are drawn： in GPS data processing of Antarctic single-point, choosing 5 IGS stations distributed all around the unknown point evenly to involve in calculation; stations which are closer to the unknown point are essential and should be in the southern hemisphere; mutual offset of polar coordinates Z is not needed to be considered.