First Flights of the Global Hawk HIWRAP Radar Over Hurricanes During GRIP

Wind measurements are crucial for understanding and forecasting tropical storms since they are closely tied to the overall dynamics of the storm. The High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) is a dual-frequency (Ka- and Ku-band), dual-beam (300 and 400 incidence angle), conical scan, solid-state transmitter-based system, designed for operation on the high-altitude (20 km) unmanned Global Hawk UAV. HIWRAP flew its first science mission on the unmanned Global Hawk (65kft ceiling) during the Genesis and Rapid Intensification Processes (GRIP) campaign conducted during August and September 2010. The Global Hawk flew for the first time over hurricanes during GRIP. The were 5 science flights over storms (Hurricanes Karl, Earl, and Matthew) during which there were as many as 20 passes over the storm center during a single flight. HIWRAP data analysis from these flights is in very early stages of processing and software development. We will present a summary of the hurrcane flights, initial data analysis, lessons learned, and future plans for HIWRAP and the Global Hawk for hurricane measurements. The HIWRAP technology aspects are being described in a paper by Li et al., and the wind retrieval algorithms are discussed in papers by Tian et al., and Guimond et al.