Passive microwave remote sensing of precipitable water vapor over Beijing-Tianjin-Hebei region based on AMSR-E

Compared with visible/infrared sensors, satellite data-based passive microwave radiometers could provide a more feasible method for retrieving precipitable water vapor (PWV). This paper presents a scheme that retrieves PWV over Beijing-Tianjin-Hebei region using satellite radiometer measurements from advanced microwave scanning radiometer (AMSR-E). For bare surfaces, the polarization difference ratio (PDR_WV) obtained from 23.8 and 18. 7 GHz was found to be sensitive to PWV. For the surface covered by vegetation, surface emissivity was retrieved by AMSR-E with the help of the MODIS atmospheric profile product. Through analyzing the statistical relationship of emissivity polarization difference, an algorithm for retrieving PWV was built. Compared with the GPS results, the root mean square error of our algorithm is 7.4 mm. Regional consistency was found between the results from MODIS and our algorithm. ©, 2015, Wuhan University. All right reserved.