The Imaging Wind and Rain Airborne Profiler (IWRAP) Data Archive

The Microwave Remote Sensing Laboratory (MIRSL) at the University of Massachusetts developed and operates the Imaging Wind and Rain Airborne Profiler (IWRAP). With support from NASA, NOAA, and ONR, UMASS has collaborated with NOAA-NESDIS and NOAA-AOC to operate the instrument aboard the NOAA WP-3D "Hurricane Hunter" aircraft since the 2002 hurricane season and for four winter experiments sampling high-latitude storms. The goals of these experiments have been to characterize storm boundary layers and to develop improved retrievals for space-based scatterometers, specifically, NASA SeaWinds Scatterometer on QuikSCAT and Advanced Scatterometer (ASCAT) which was developed by ESA on behalf of EUMETSAT. IWRAP is a conically-scanning, dual-frequency (C-and Ku-band) coherent radar with dual-polarization capability. The incidence angles are nominally: 30, 35, 40, and 50 degrees. At times, the instrument has been configured to address specific scientific and engineering problems. Examples include: C-band measurements of high incidence angle backscatter for ASCAT validation, and C-band horizontal polarization measurements to develop a high wind speed geophysical model function (GMF). Independent measurements of surface wind speed and column integrated rain rate are made coincidently with the UMass Simultaneous Frequency Radiometer (USFMR) and AOC Stepped Frequency Microwave Radiometer (SFMR). Since 2005, IWRAP has operated in a raw data mode, recording individual radar pulses to enable the separation of near surface backscatter contributions (i.e. surface scattering versus volume scattering). The intensity of tropical cyclones ranged from tropical storm to category five hurricane, and high-latitude storms with up to hurricane force winds.