利用地基GPS测量大气水汽廓线的方法

Abstract

GPS倾斜路径的湿延迟反映了大气中水汽的三维非均匀分布,通过准确确定空间各卫星对地面各接收机的倾斜路径湿延迟,就可以利用断层扫描技术,确定大气层中水汽的三维分布和变化,从而增加目前还相对缺乏的大气水汽探测。文章就这方面介绍了国际上利用地基GPS测量倾斜路径大气湿延迟的两类方法(单点定位方法和双差定位方法)以及应用断层扫描技术利用这些观测进行水汽廓线遥感探测的两类方法(附加约束法和卡尔曼滤波法),并对这些方法的优缺点进行了初步的比较和探讨。 The slant wet delay of GPS signals is subjected to the non-uniform distribution of the water vapor in the atmosphere.The three dimensional field of water vapor can be recovered by the computerized tomography(CT) method through accurately determining the slant wet delays from satellites to antennas on the ground.Two sorts of methods for determining the slant wet delays,the point precise positioning(PPP) and the double-difference method,are introduced.Two CT approaches for obtaining the water vapor profiles((Gaussian) constraint and the Kalman filtering) are discussed.