Presenting Author: Mr. Michael Caruso
The Center for Southeastern Tropical Advanced Remote Sensing (CSTARS) of the University of Miami (UM) has teamed with the Canadian Space Agency (CSA) and the U.S. National Oceanic and Atmospheric Administration / Atlantic Oceanographic and Meteorological Laboratory (NOAA/AOML) in a program to analyze C-band Synthetic Aperture Radar (SAR) data acquired over hurricanes. This program was started in 1999 and has collected over 300 images of tropical cyclones. Wind fields under hurricane conditions are retrieved from C-band SAR data acquired by RADARSAT-1. RADARSAT-1 is a right looking radar, which acquires images at C-band with horizontal (HH) polarization in transmit and receive. Wind speeds are computed from the SAR measured normalized radar cross section utilizing the scatterometer CMOD5 model function. The model function was modified for the Radarsat-1 HH polarization using a C-band polarization ratio. To retrieve winds using SAR, the wind direction must be known a-priori or estimated reasonably. Wind directions were obtained using numerical model winds and linear features visible in the SAR image associated with wind streaks. High resolution Synthetic Aperture Radar (SAR) winds fields over the ocean show spatial variability that have not been modeled or measured by any other technique. This includes the features produced by topographic influences in coastal regions and by hurricanes near the eye wall or in the outer bands. While the winds derived from SAR provide valuable information about the high resolution structure of the wind field, the winds also contain systematic, random and nonlinear errors. In this analysis, the high resolution two-dimensional structure of SAR derived wind estimates of hurricanes is compared with high resolution scatterometer and numerical model winds. The SAR derived wind fields show unprecedented details of the hurricane eye, including location, shape and size. These comparisons demonstrate the potential usefulness of the high resolution wind fields such as those from XOVWM.
2019 International OVWST Meeting
May 29-31 in Portland, Maine, USA