Advanced dropsondes that could effectively be guided through atmospheric regions of interest such as volcanic plumes could enable unprecedented observations of important atmospheric phenomena. Innovative Dynamics, Inc. proposes to develop a flight ready optical sensor package to provide hazardous volcanic ash and particulate information within commercial airspace. The probe will initially be used as a dropsonde from a UAV but eventually be carried by all aircraft. This volcanic ash particulate information would then be incorporated into standard E-PIREP reports as well as distributed via air traffic controllers. The innovation is a new capability for making in-situ measurement of cloud particulates to improve pilot awareness of hazardous operating conditions, such as those recently experienced by aircraft engines operating in the North Atlantic near Iceland. Cloud and Ash particulate information is currently obtained by positioning a satellite to a location, produces limited data, and is cost prohibitive. IDI proposes to develop a flight deployable optical probe which will determine various airborne particulates such as volcanic ash particle size and density. The probe packaging will be developed to be compatible with existing RQ-4 dropsonde hardware, will be low-cost, low-weight and will be able to be deployed on various platforms, i.e., radiosondes and other payload recovery vehicles.