Assessment of periodic sub-diurnal Earth rotation variations at tidal frequencies through transformation of VLBI normal equation systems
Assessment of periodic sub-diurnal Earth rotation variations at tidal frequencies through transformation of VLBI normal equation systems
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DOI：
10.1007/s00190-011-0457-z
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发表时间：
2011-03
影响因子：
4.4
通讯作者：
T. Artz;Sarah Tesmer née Böckmann;A. Nothnagel
中科院分区：
文献类型：
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作者：
T. Artz;Sarah Tesmer née Böckmann;A. Nothnagel
基于甚长基线干涉测量（VLBI）观测过程的法方程（NEQ）系统变换，提出了一个地球自转参数（ERPs）日变化和亚日变化的经验模型。NEQ系统，包含高分辨率的极运动和UT 1-TAI的时间分辨率为15分钟的生成，然后转换为潮汐ERP模型的系数来解决。为了研究该模型的质量，与全球定位系统（GPS）的经验模型，另一个VLBI模型和国际地球自转和参考系服务（IERS）的公约所采用的模型进行了比较。这些模型的绝对系数在极移的7.5 μ s和UT 1-TAI的0.5 μ s范围内几乎完全一致。存在几个更大的差异，本文对此进行了讨论。为了能够比较的模型估计与连续VLBI活动的结果，其中信号与周期为8和6小时被检测到，条款在ter-and quarter-daynuralband被包括在潮汐ERP模型。不幸的是，几乎没有共同的功能与连续VLBI活动或ERP预测的结果，在这些潮汐带可以看到。
We present an empirical model for periodic variations of diurnal and sub-diurnal Earth rotation parameters (ERPs) that was derived based on the transformation of normal equation (NEQ) systems of Very Long Baseline Interferometry (VLBI) observing sessions. NEQ systems that contain highly resolved polar motion and UT1-TAI with a temporal resolution of 15 min were generated and then transformed to the coefficients of the tidal ERP model to be solved for. To investigate the quality of this model, comparisons with empirical models from the Global Positioning System (GPS), another VLBI model and the model adopted by the conventions of the International Earth Rotation and Reference Systems Service (IERS) were performed. The absolute coefficients of these models agree almost completely within 7.5 μ as in polar motion and 0.5 μsin UT1-TAI. Several bigger differences exist, which are discussed in this paper. To be able to compare the model estimates with results of the continuous VLBI campaigns, where signals with periods of 8 and 6 h were detected, terms in the ter- and quarter-diurnal band were included in the tidal ERP model. Unfortunately, almost no common features with the results of continuous VLBI campaigns or ERP predictions in these tidal bands can be seen.