摘要
利用GRACE观测值对框架站季节项进行建模,并以全球分布的139个连续观测的基准站为例,分析季节性变化在参考框架实现过程中对坐标转换参数以及测站的影响。对80%以上全球站的单日解而言,在附加季节项改正之后,其单位权中误差减小的幅度接近1 mm,其中用年周期-半年周期和非参数方法对季节性变化建模,单位权中误差最大分别减小1.4和1.6 mm。
In this study, a seasonal loading model was imported into the ITRF2008 solutions based on GRACE （Gravity Recovery And Climate Environment）measurements to simulate hydrological loading, and comparison of the model to the original ITRF2008 for global reference frame realization was made. The seasonal components were simula- ted using either annual and semi-annual terms or a non-parametric approach. Misfitting of the WRMS（ Weighted Root Mean Squares）after 7-parameter transformation calculated with the model decreases compared to that with the original ITRF2008 for more than 80% of daily GPS solutions. In general, the range of seasonal variations of daily solution at all sites is slightly larger in use of the seasonally augmented ITRF model. However, the results calculated with the model are more consistent with observed seasonal variations for 84% of the GPS sites. The findings mean that the use of the range of seasonal variations in the coordinate time series is decreased in use of ITRF2008 without seasonal terms rela- tive to the true loading deformation,and that the results calculated with the TRF model included seasonal variations are more consistent with the observed GPS time series.
出处
《大地测量与地球动力学》
CSCD
北大核心
2014年第6期50-54,59,共6页
Journal of Geodesy and Geodynamics
基金
国家自然科学基金项目(41304014
41204001
41274037)
国家863计划项目(2013AA122501)
海岛(礁)测绘技术国家测绘地理信息局重点实验室项目(2013B04)
地球内部多尺度成像湖北省重点实验室项目(SMIL-2014-10)
