Impact of loading displacements on SLR-derived parameters and on the consistency between GNSS and SLR results
Impact of loading displacements on SLR-derived parameters and on the consistency between GNSS and SLR results
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DOI：
10.1007/s00190-013-0644-1
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发表时间：
2013-05
影响因子：
4.4
通讯作者：
K. Sośnica;D. Thaller;R. Dach;A. Jäggi;G. Beutler
中科院分区：
文献类型：
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作者：
K. Sośnica;D. Thaller;R. Dach;A. Jäggi;G. Beutler
潮汐和非潮汐载荷力引起的地球表面位移与高精度空间大地测量有关。国际科学界建议在观测一级应用其中一些校正，例如，海洋潮汐负荷（OTL）和大气潮汐负荷（ATL）。一般建议不对国际地球自转和参照系服务的产品采用非潮汐位移校正，特别是大气非潮汐负荷、海洋和水文非潮汐校正。我们评估和比较OTL，ATL和ANTL对SLR衍生参数的影响，通过重新处理12年的SLR数据，考虑和忽略个别校正。结果表明，加载位移不仅对台站长期稳定性有影响，而且对地心坐标、地球自转参数和卫星轨道也有影响。应用加载校正降低了地心坐标和台站坐标时间序列中的年信号幅度。采用OTL、ATL和ANTL改正后，SLR站三维坐标重复性的总体改善率分别为19.5%、0.2%和3.3%。没有加载校正的解决方案。ANTL校正在光学（SLR）和微波（GNSS，VLBI，DORIS）空间大地测量观测技术的组合中发挥着至关重要的作用，因为所谓的蓝天效应：SLR测量只能在无云的天空条件下进行-通常在高气压条件下，当地壳变形时，而微波观测与天气无关。因此，在观测水平上应用加载校正改进了SLR导出的产品以及与基于微波的结果的一致性。我们评估蓝天的影响SLR站和GNSS和SLR解决方案之间的一致性改善时，ANTL校正包括在内。对于内陆台站，忽略ANTL校正可能导致SLR和GNSS解之间的不一致，最高可达2.5 mm。因此，在应用ANTL校正时，估计的GNSS-SLR坐标差更好地对应于同地台站的局部关系。
Displacements of the Earth’s surface caused by tidal and non-tidal loading forces are relevant in high-precision space geodesy. Some of the corrections are recommended by the international scientific community to be applied at the observation level, e.g., ocean tidal loading (OTL) and atmospheric tidal loading (ATL). Non-tidal displacement corrections are in general recommended not to be applied in the products of the International Earth Rotation and Reference Systems Service, in particular atmospheric non-tidal loading (ANTL), oceanic and hydrological non-tidal corrections. We assess and compare the impact of OTL, ATL and ANTL on SLR-derived parameters by reprocessing 12 years of SLR data considering and ignoring individual corrections. We show that loading displacements have an influence not only on station long-term stability, but also on geocenter coordinates, Earth Rotation Parameters, and satellite orbits. Applying the loading corrections reduces the amplitudes of annual signals in the time series of geocenter and station coordinates. The general improvement of the SLR station 3D coordinate repeatability when applying OTL, ATL and ANTL corrections are 19.5 %, 0.2 % and 3.3 % respectively, w.r.t. the solutions without loading corrections. ANTL corrections play a crucial role in the combination of optical (SLR) and microwave (GNSS, VLBI, DORIS) space geodetic observation techniques, because of the so-called Blue-Sky effect: SLR measurements can be carried out only under cloudless sky conditions—typically during high air pressure conditions, when the Earth’s crust is deformed, whereas microwave observations are weather-independent. Thus, applying the loading corrections at the observation level improves SLR-derived products as well as the consistency with microwave-based results. We assess the Blue-Sky effect on SLR stations and the consistency improvement between GNSS and SLR solutions when ANTL corrections are included. The omission of ANTL corrections may lead to inconsistencies between SLR and GNSS solutions of up to 2.5 mm for inland stations. As a result, the estimated GNSS–SLR coordinate differences correspond better to the local ties at the co-located stations when applying ANTL corrections.