Development of an airborne integrated phase Doppler interferometer/imaging probe for accurate cloud droplet size distribution measurement

"This Phase I SBIR proposal seeks to investigate the feasibility of developing anoptical probe based on phase Doppler interferometry (PDI) for reliable and accuratemeasruement of the cloud droplet size distribution from airbonre platforms. The keyfeatures of this device are high accuracy and precision droplet sizing, large dynamicrange, accurate concentration measurement throughout the entire instrument dynamic range,very low coincidence errors, and large counting volume. The other key featues of theproposed instrument are: low cost, low power consumption, compactness, and real-time datamonitoring and transmission to ground-based facilities. Additionally, we propose toalso investigate the feasibility of simultaneous (in the same view volume) discriminationof ice crystals from water drops, and subsequent imaging of these particles. Theintegration of the imaging probe with a phase-Doppler system will permit measurementof both spherical and non-spherical particles. This instrument package representsa significant improvement over past cloud droplet measurement devices, and therebydirectly addresses the need for atmospheric instruments/sensors that the Navy hasidentified in topic N02-61 of the FY2002 SBIR solicitation. Clouds are a very important component of the climate system because of theireffects on longwave and shortwave radiation, atmospheric heat, moisture, andmass transport, precipitation, and atmospheric chemistry. Clouds and fee