Retrieval of cloud liquid water content and effective droplet diameter from multiply scattered lidar returns

Supercooled cloud and precipitation water droplets cause in-flight icing of aircraft lifting and control surfaces and thus constitute a safety hazard to aviation. There is a growing interest in the development of remote sensors to warn of the danger zones. A known characteristic of these zones is that they are spatially and temporally variable, hence the need for real time detection. We have tested in two coordinated field experiments the DREV multiple-fieldof- view (MFOV) lidar as a means of characterizing icing conditions. The required information is the temperature, the phase, the liquid water content arid the droplet size of clouds and precipitation. The last three quantities are obtainable, within limits, with the MFOV lidar. The paper briefly describes the MFOV measurement and solution methods, and reports on sample retrieval results of liquid water content and droplet effective diameter. These data are directly applicable to the remote characterization of in-flight icing conditions. The accuracy of these lidar solutions is currently estimated at 30-40%.