Ground-Based GPS Tomography of Water Vapor: Analysis of Simulated and Real Data
Ground-Based GPS Tomography of Water Vapor: Analysis of Simulated and Real Data
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DOI：
10.2151/jmsj.2004.551
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发表时间：
2004-03
影响因子：
3.1
通讯作者：
L. Gradinarsky;P. Jarlemark
中科院分区：
文献类型：
--
作者：
L. Gradinarsky;P. Jarlemark
我们提出的概念，一些使用的方法，和能力的技术被称为GPS断层扫描。它是用于反演的三维分布，由于大气水汽的质子活动。我们讨论了目前使用的GPS层析成像中主要可观测量、倾斜路径延迟的检索方法及其缺点。GPS倾斜延迟的微波辐射计的独立数据的比较。从层析成像的角度来看，我们集中在检索的垂直结构的湿重活动的能力。为此，我们提出并应用两种层析反演方法。两者都是基于卡尔曼滤波技术，其中利用了预期的统计行为的活动。两者之间的区别在于卡尔曼滤波器的协方差矩阵的构造方式。我们的研究基于模拟和真实的数据，从地面网络的8个GPS接收机在瑞典哥德堡。结果表明，目前GPS层析成像技术的局限性在于反演的湿倾斜延迟存在误差，且其几何分布较差。
We present the concept, some of the approaches used, and the capabilities of the technique referred to as GPS tomography. It is used for retrieval of the 3-dimensional distribution of the refractivity due to atmospheric water vapor. We discuss the presently used methods for retrieval of the primary observable in the GPS tomography, the slant path delay, as well as their shortcomings. Comparisons of GPS slant delays to independent data from a microwave radiometer are included. From a tomographic point of view we concentrate on the capabilities to retrieve the vertical structure of the wet refractivity. For this purpose we present and apply two methods for tomographic inversion. Both are based on the Kalman filtering technique, where the expected statistical behavior of the refractivity is utilized. The difference between the two is in the way the covariance matrix of the Kalman filter is constructed. We base our study on simulated and real data from the ground network of 8 GPS receivers operating in Goteborg, Sweden. The results demonstrate that at present the limitations of the GPS tomographic technique are errors in the retrieved wet slant delays and their poor geometric distribution.