Physical Sciences Inc. proposes to develop a compact, multiwavelength LIDAR with polarization analysis capability that will be able to identify volcanic ash clouds at distance. The system will be developed specifically for airborne deployment, including on Unmanned Aerial Systems. A UAS-equipped with such a LIDAR could provide valuable supplementary information to that available from existing and planned satellite assets for defining and tracking volcanic ash plumes. The system footprint will be minimized by taking advantage of all solid-state laser transmitters such as emerging metal doped fiber amplifiers. The Phase I program will determine the most appropriate wavelengths for use via system modeling and then will select laser transmitter hardware. Additional modeling will determine the transmit pulse energy and receive aperture size. The system will be designed to be eyesafe. A complete conceptual design for an Airborne Multiwavelength Lidar will be developed. The technology readiness level at the entrance to the Phase I program is estimated to be 2 and at the exit of the program will be 3. The Phase II program will design, fabricate and ground test a prototype LIDAR system. Opportunities for a flight demonstration will be identified.