长三角地区GPS斜路径观测值分布分析

DISTRIBUTION OF GPS SLANT DELAY FOR WATER VAPOR TOMOGRAPHY IN YANGTZE RIVER DELTA

分析长三角地区GPS连续监测站斜路径水汽观测值的分布情况,特别是不同空间分辨率和时间分辨率条件下,斜路径观测值对网格的覆盖情况,研究了利用此区域网进行水汽三维层析的可行性。结合数值预报资料,采取模拟仿真方法,研究了该区域网用于水汽三维层析的加密方案。实验分析可知,长三角GPS监测网测站几何结构较差,观测值分布不均匀,给层析解算带来一定困难。同时,加密GPS监测网能够从整体上提高层析的精度,主要是改善了底层格网内水汽的垂直结构。

The distribution of GPS slant observations taken by continuously operating Yangtze River Delta GPS network this work is described . The distribution of the grid coverage of slant data at different temporal and spatial resolutions are given. From this, the feasibility of 3 D water vapor tomography in a test region is discussed. At last, a set of additional instruments in GPS network scheme for water vapor tomography is researched by using simulation method with ECMWF data. It is concluded that the bad geographic distribution of GPS network in Yangtze River Delta causes difficulties in tomography, and the overall accuracy can be improved by adding some stations, especially in lower atmosphere.