Retrieval of water vapor profiles using measurements from a millimeter-wave imaging radiometer

A six-channel airborne total-power Millimeter-wave Imaging Radiometer (MIR) was built recently to provide measurements of atmospheric water vapor, clouds, and precipitation. It measures radiation at the frequencies of 89, 150, 183.3±1, 183.3±3, 183.3±7, and 220 GHz to an accuracy of ±1 K. It is capable of estimating water vapor concentrations at different depths of the atmosphere between surface and ~10 km altitude. This paper illustrates the capability of the new radiometer in the profiling of atmospheric water vapor. In particular, the retrieval from the measurements at view angles other than nadir was explored. The retrieved profiles are compared with those measured by the rawinsondes and the ground-based Raman lidar