中文摘要：

进行低高度角观测是GPS（Global Positioning System）气象学的发展趋势，其中发展高精度的低高度角的大气静力学延迟修正是主要的关键技术．比较了3种计算无线电波从空间到地面接收机的大气静力学延迟修正方法：（1）在大气球对称假设下用探空气球资料路径积分得到大气静力学延迟；（2）在大气球对称假设下用NCEP（National Centers for Environmental Prediction）再分析资料得到大气静力学延迟；（3）用Niell的大气静力学映射函数得到大气静力学延迟．与2001年中国地区89个探空气球站资料计算得到的大气静力学映射函数比较结果显示：NCEP再分析资料路径积分的方法在低高度角（5°以下）的精度好于Niell映射函数模型约5倍．

英文摘要：

It is a tendency of GPS （Global Positioning System） meteorology to carry out observations at low elevation angle. The correction of high precision atmospheric hydro- static delay at low elevation angle is a key issue. Three different methods, which calculate atmospheric hydrostatic delay of radio waves propagating from space to a ground-based receiver, are compared. They are： （1） path integration under the assumption of atmospheric spherical symmetry using radiosonde data; （2） the same method as above, but using NCEP （National Centers for Environmental Prediction） reanalysis data; （3） the Niell＇s hydrostatic mapping function. Compared with the atmospheric hydrostatic delay correction calculated from the 89 radiosonde data of China in 2001, the accuracy of method （2） is about 5 times better than that of method （3） on condition that the elevation angles are less than 5°.