Near-Real-Time IWRAP 3D Wind Retrievals

Historically, the Imaging Wind and Rain Airborne Profiler (IWRAP) radar system has been used as a research instrument aboard the National Oceanic and Atmospheric Administration (NOAA) WP-3D Hurricane Hunter airplanes collecting data for postflight processing and analysis. For the 2020 hurricane season, we demonstrated an initial near-real-time (NRT) atmospheric 3D wind processing capability, where retrievals were produced during a flight and transmitted to servers on the ground. Subsequently, the 3D wind retrieval algorithms have advanced to use the Doppler spectrum sampled by the IWRAP radars to reject surface clutter. This allowed wind retrievals closer to the ocean surface but increased the complexity of the retrieval processor. This article describes the latest technology implemented in the IWRAP radar system from the raw measurement to the final NRT 3D wind retrieval product, including the calibration/validation methodologies.