基于多技术全球参考框架的维持及应用分析

Analysis of application and maintenance of multi-technical based global reference frame

全球基准从参与构建框架的方式来说分为长期框架和短期框架(历元框架),由于框架点运动的非线性特性,长期框架构建的基准无法描述毫米级地球表面运动,常会采用短期框架来描述。短期框架实现时严格说应该保证空基(卫星轨道)和地基(ITRF、IGS)的一致性,再者,空间大地测量技术综合框架与单一技术基准在构建和维持上同样存在差异,这些不一致都将导致地面站坐标表达的差异。不同时期长期框架维持差异性及精度也是我国框架维持需考虑的问题,该文就以上各类框架构建策略不同对实际点位的影响进行了比较分析并给出结论,供我国高精度基准建设参考。

Global reference frames can be divided into long-term reference frame and short-term reference frame according to the way that has been constructed.Long-term reference frame could not be used to describe earth surface movement with mm accuracy because of site non-linear movement,while short-term reference frame is often used instead.Short-term reference frame should be rigorously implemented under assurance of the consistent of space datum(satellite orbits)and ground datum(ITRF or IGS),and also,the coordinate difference also exists between the one derived from combined reference frame and the one from GPS technique,all these inconsistences will result in different position presentation.The accuracy of transformed-coordinate from the different epoch determined on different ITRFs is the problem that needs to be paid attention to for China geodetic coordinate system2000(CGCS2000)maintenance.All of those stated above,including different strategies applied in frame implementation,would be discussed and analyzed in this paper,and then some conclusion for later reference would be reached.