Unmanned Aerial Vehicle Dropsondes with Global Positioning System Windfinding.

Detailed, quantitative, atmospheric data are essential for accurate analyses and forecasting of mesoscale phenomena for military and civilian applications. Over remote areas, environmental satellites provide qualitative and broadscale quantitative information more suitable for synoptic scale analyses. Because satellite instruments for measuring atmospheric variables have relatively large footprints and vertical resolutions, airborne systems remain the only reliable source of detailed, quantitative, accurate data for remote mesoscale areas, especially 500 by 500 km or smaller. Within remote or hazardous regions, use of manned aircraft for gathering atmospheric data may not be feasible because of the high risk to personnel and expensive equipment. Unmanned aerial vehicles can carry small sensors and dropsondes into these areas, at no risk to personnel and at a very low cost. The Battlefield Environment Directorate of the Army Research Laboratory led the development of a dropsonde with Global Positioning System GPS windfinding capability, assisted by the Physical Sciences Laboratory of New Mexico State University. This report briefly discusses the dropsondes and presents the results of the flight test at the conclusion of phase 1. Phase 1 investigated current off-the-shelf capability as of late 1994 with a modification to obtain wind profiles via GPS techniques. Plans include a phase 2 that will seek to produce proof-of-concept prototype dropsondes and dispenser.