基于非线性运动分析的CGCS2000下我国CORS站运动特征

Characteristics of the non-linear movement of CORS network in China based on the CGCS2000 frame

CGCS2000(中国地心坐标系统2000)下CORS(全球导航卫星系统连续运行参考站)站的非线性运动主要受到地壳非构造形变信息、框架点公共误差信息和观测误差信息的组合影响,分析我国CORS站坐标时间序列中包含的非线性运动信息是维护CGCS2000坐标框架精确性、可靠性的基础.本文研究方法首先采用国际卫星对地观测数据及相关地球物理模型,计算了由质量负荷效应造成的地壳非构造形变,并以此修正了这些非构造形变对国家CORS站坐标时间序列的影响.其次采用主成分空间滤波算法(PCA)提取质量负荷改正后的CGCS2000坐标框架公共误差(Common Mode Errors,CME)的时空特性.最后采用最大似然法定量估计了负荷改正和滤波后的国家CORS网坐标时间序列的噪声特性,采用加权最小二乘法评定了考虑不同噪声影响的CGCS2000框架下的国家CORS网年速度估值和实际精度.

Non-linear movement of Chinese CORS network based on the CGCS2000（Chinese geocentric 3D coordinate system） frame is mainly affected by the combined factors composed of non-tectonic crustal deformation signals,Common Mode Error（CME） in coordinate frame and error factor in observation.We can promote the accuracy and reliability of CORS network based on the analysis and modeling of the non-linear movement information in the CORS position time series.In this paper,we firstly use the international Earth satellite data and geophysical models to calculate non-tectonic crustal deformation in coordinate time series of CORS network based on the CGCS2000 caused by mass loading effects.Based on the quantitative analyses,we corrected the quantity of mass loading effects in the position time series of CORS stations.Secondly,after removing these surface mass loading effects,a spatial filtering algorithm based on principal component analysis is employed to remove the common mode errors of CGCS2000 from the daily position time series.Finally,the noise characteristic after mass loading correction and filtering is estimated quantitatively with the criterion of maximum likelihood estimation,and the annual speed and the actual accuracy of national CORS network are evaluated with the weighted least squares method.