中文摘要：

介绍了应用全球定位系统（GPS）和太阳光度计估算大气水汽总量的方法。大气中的水汽会对GPS信号的传播造成显著的影响，故可以利用GPS观测估算水汽总量或可降水量（PW）；在近红外940nm波段，水汽对太阳直射辐射的吸收作用会直接影响到太阳光度计观测的信号，利用水汽吸收透过率与水汽量的关系，应用太阳光度计的辐射观测资料也可以反演出无云情况下的水汽总量。将锡林浩特观象台2008年5～7月的GPS、CE-318型太阳光度计和探空仪3种观测的水汽量进行了比较，三者对水汽量的变化趋势描述较为吻合，相关系数在0．88以上，说明GPS和太阳光度计都能捕捉到大气中的水汽变化信息；但在水汽量的具体数值上存在差异。统计分析表明：相对于探空来说，GPS-PW稍高于探空值约0．18g／cm2，太阳光度计PW值则低于探空。太阳光度计便于携带，观测简便；GPS可全天观测无需标定，利用GPS-PW对太阳光度计反演中的模拟参数进行校正是一种可行的方法。

英文摘要：

The methods of integrated water vapor estimates in the atmosphere using the GPS and the sun photometer are intro- duced. The atmospheric water vapor is able to affect the propagation of GPS signal. Therefore, the GPS can be used to esti- mate the integrated water vapor amount or precipitable water （PW）. Water vapor can absorb solar radiation in the near infrared bands of 940 nm, which can directly affect the signals observed by the sun photometer. By applying the relation between at mospheric transmittance and water vapor amount, precipitable water in clear sky can be determined using measurements from the sun photometer. The comparison among the GPS, the CE-318 sun photometer and the radiosonde for water vapor estimation is presented from May to July in 2008 at Xilinhaote station. The three methods are correlated well on describing water vapor trendeney with correlation coefficient greater than 0.88, implying that both the GPS and the sun photometer can measure water vapor information in almost the same degree. But there is a difference in water vapor absolute values. Statistical analysis indicates that the GPS-PW is 0.18 g/cm2 higher than the radiosonde and, the value of the sun photometer PW is lower than that of the radiosonde. The sun photometer is easy to carry and operate relatively. The GPS can be used under all weather conditions with no calibrations needed. The GPS appears to be used as a calibration tool for the parameters in the water vapor retrieval of the sun photometer.