Vienna mapping functions in VLBI analyses
Vienna mapping functions in VLBI analyses
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DOI：
10.1029/2003gl018984
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发表时间：
2004-01-02
影响因子：
5.2
通讯作者：
Schuh, H
中科院分区：
文献类型：
--
作者：
Boehm, J;Schuh, H
在过去的几年中，数值天气模式（NWM）的研究，以改善映射函数，用于对流层延迟模拟VLBI和GPS数据分析。维也纳映射函数VMF基于通过NWM的直接光线跟踪，因此它们能够利用NWM中提供的全部信息。另一方面，等压映射函数IMF使用从NWM计算的中间参数。在这项研究中，来自欧洲中期天气预报中心（ECMWF）的气压水平数据被用来确定VMF和IMF的系数。用于IVS-R1和IVS-R4 VLBI会话的分析，与Niell映射函数NMF相比，两种映射函数均提高了基线长度的重复性（IVS-R1的重复性接近10%，IVS-R4的重复性接近5%）。
In the past few years, numerical weather models (NWM) have been investigated to improve mapping functions which are used for tropospheric delay modeling in VLBI and GPS data analyses. The Vienna Mapping Functions VMF are based on direct raytracing through NWM, and so they are able to exploit the full information provided in the NWM. On the other hand, the Isobaric Mapping Functions IMF are using intermediate parameters calculated from the NWM. In this study, pressure level data from ECMWF (European Centre for Medium-Range Weather Forecasts) are applied to determine the coefficients of the VMF and the IMF. Used for the analyses of IVS-R1 and IVS-R4 VLBI sessions, both mapping functions improve the repeatability of baseline lengths (by similar to10% for IVS-R1 and similar to5% for IVS-R4) compared to the Niell Mapping Functions NMF.