Microwave radiometer for passively and remotely measuring atmospheric water vapor profiles

Radiometric Corporation proposes to apply a new microwave technology to profiling of atmospheric water vapor. Water vapor is the most significant and most highly variable of greenhouse gases. It is also the most significant and highly variable atmospheric constituent in the formation of weather and in the transfer of atmospheric heat. Yet it remains one of the most poorly characterized of meteorological parameters. In spite of their high cost, inaccuracy, and noncontinuous nature, radiosondes (RAOBs) are still the common method of profiling atmospheric water vapor. There are no all-weather remote sensing technologies in existence or in development that can remotely profile water vapor; other know technologies are defeated by the presence of cloud. The inversion method proposed herein involves profiling the power spectrum received at the surface of a pressure broadened microwave water vapor emission line. A prototype profiling radiometer is the built and operated in parallel with NWS (RAOB) releases. We further propose to apply heretofore unexplored mathematical inversion methods to retrieve the vapor profile from the instrument observables. We will employ several experts in several fields of mathematical inversions, including neural networking, iterative, and seismic inversion methods. These methods will be tested for accuracy under a broad spectrum of atmospheric conditions using data from RAOB soundings as well as synthetic profiles. This instrument will be capable of water vapor and temperature profiles along slanted (elevated) paths as well as zenith.