THE APPROACH TO REMOTE SENSING OF WATER VAPOR BASED ON GPS AND LINEAR REGRESSION T_m IN EASTERN REGION OF CHINA

The approach to remote sensing of water vapor by using global positioning systems(GPS) isdiscussed.In order to retrieve the vertical integrated water vapor(IWV) or the precipitable water(PW),the weighted "mean temperature" of the atmosphere,Tm would be estimated to the specificarea and season.Tm depends on surface temperature,tropospheric temperature profile,and thevertical distribution of water vapor.The surface temperature dependence is borne out by acomparison of Tm and the values of surface temperature Ts using radiosonde profiles of BeijingStation(No.54511) throughout 1992.The analysis of radiosonde profiles spanning a one-yearinterval(1992) from sites in eastern region of China with a latitude range of 20-50°N and alongitude range of 100-130°E yields the coefficients a and b of a linear regression equation Tm=a+bTs.