AN EVALUATION OF A 94-GHZ RADAR FOR REMOTE-SENSING OF CLOUD PROPERTIES

The performance of a 94-GHz radar is evaluated for a variety of cloud conditions. Descriptions of the radar hardware, signal processing, and calibration provide an overview of the radar's capabilities. An impor tant component of the signal processing is the application of two clou d-mask schemes to the data to provide objective estimates of cloud bou ndaries and to detect significant returns that would otherwise be disc arded if a simple threshold method for detectability was applied to th e return power. Realistic profiles of atmospheric pressure, temperatur e, and water vapor are used in a radiative transfer model to address c lear-sky attenuation. A physically relevant study of beam extinction a nd backscattering by clouds is attempted by modeling cloud drop size d istributions with a gamma distribution over a range of number concentr ations, particle mean diameters, and distribution shape factors; cloud liquid water contents and mean drop size diameters reported in the li terature are analyzed in this context. Results of observations of a nu mber of cloud structures, including marine stratocumulus, cirrus, and stratus and cirrus associated with a midlatitude cyclone are described .