坐标参考框架长期解内约束模型  

Fusion Model for Long‑Term Solutions to the Terrestrial Reference Frame Using Internal Constraints

作　　者：曾安敏 明锋[1,2] 吴富梅 ZENG Anmin;MING Feng;WU Fumei(State Key Laboratory of Geo-Information Engineering,Xi'an 710054,China;Xi'an Institute of Surveying and Mapping,Xi'an 710054,China)

机构地区：[1]地理信息工程国家重点实验室,陕西西安710054 [2]西安测绘研究所,陕西西安710054

出　　处：《武汉大学学报（信息科学版）》2022年第9期1447-1451,1459,共6页Geomatics and Information Science of Wuhan University

基　　金：国家重点研发计划(2020YFB505801);国家自然科学基金(42074006)。

摘　　要：地球参考框架是一切测绘活动、地球科学研究的物理基础。目前,地球参考框架常采用长期解的形式,即利用一组全球分布的基准站在某一参考历元的坐标和速度来表示。由于观测有误差,且各基准站又具有非线性变化,故需要对不同历元的瞬时地球参考框架进行累积,形成稳定的长期参考框架。以不同历元观测数据得到的瞬时参考框架成果为输入,构建了一种基于多历元观测数据建立参考框架长期累积解的融合模型。从坐标转换模型和测站坐标的时变模型出发,详细推导了建立长期解的函数模型,依据该函数模型的秩亏数设计了转换参数的内约束基准。采用2010⁃08—2014⁃12的国际全球导航卫星系统服务第2次处理结果进行试算,并与国际地球参考框架2014成果进行了对比。结果表明,X、Y、Z方向标准偏差分别为3.45 mm、4.04 mm、2.84 mm,速度精度分别为1.53 mm/a、1.46 mm/a、1.21 mm/a,X、Y、Z方向的加权均方根误差优于3 mm。Objectives:A terrestrial reference system(TRS) is a spatial reference system corotating with the Earth in its diurnal motion in space. A terrestrial reference frame(TRF) is defined as the realization of a TRS, through the realization of its origin, orientation axes and scale, and their time evolution. The TRF is the basis of all surveying and mapping activities and earth science research. Usually, its realization is achieved by a set of physical points with precisely determined coordinates in a specific coordinate system.Methods:The instantaneous positions obtained from different epoch observations are with respect to different reference frames. It is necessary to accumulate the instantaneous positions to form a stable long-term reference frame. Taking the instantaneous positions obtained from different epoch observations as input, a fusion model for the long-term solutions to a TRF is designed. The function model for the long-term solutions is deduced in detail considering the coordinate transformation model and the time-varying model of station coordinates. The rank deficiency is solved by applying internal constraints to the Helmert transformation parameters.Results:The daily solutions spanning from 2010-08-2014-12 from the second reprocessing of International Global Navigation Satellite System Service are used for calculation, and the results are compared with that of the international terrestrial reference frame 2014(ITRF2014). The results show that for daily solutions the standard deviation is 3.45 mm, 4.04 mm, and 2.84 mm for X, Y and Z directions,respectively, and the weighted root mean square is better than 3 mm for all three directions. In terms of velocity, the accuracy is 1.53 mm/a, 1.46 mm/a, and 1.21 mm/a for X, Y and Z directions, respectively.Conclusions:The derived TRF using the fusion model is consistent with ITRF2014, and the results validate the correctness and reliability of our fusion model, which can provide a theoretical basis for the establishment of the reference frame.

关 键 词：地球参考框架 长期解 坐标转换 融合模型 内约束 

分 类 号：P227[天文地球—大地测量学与测量工程]