Synthetic Aperture Radar and Optical Remote Sensing of Crop Damage Attributed to Severe Weather in the Central United States

As defined in the United States by its National Oceanic and Atmospheric Administration (NOAA) and National Weather Service (NWS), severe thunderstorms are those that produce either tornadoes of any duration and intensity, hail with diameter in excess of 2.54 cm (1 in.), or winds in excess of 26 ms
^-1
(58 mph). These storms often produce heavy rains as individual events and regional flooding if aggregated over multiple days of similar events. Damage to the land surface, urban settlements, and infrastructure is often apparent visually in commercial high resolution and moderate resolution, publicly available satellite imagery, though frequently limited by cloud cover. Synthetic aperture radar (SAR) complements optical remote sensing approaches to identify damage to crops and vegetation from these storms. SAR provides an opportunity for nearly all-weather remote sensing of the land surface through changes in backscatter and coherence among paired images of disparate time but common viewing angle. Changes in polarized backscatter and multi-image coherence observed in regions observed having experienced severe thunderstorms are apparent in regions of hail, wind, and tornado damage to the land surface. In this study, SAR techniques are used to objectively map damage to vegetation caused by severe weather and complemented by traditional measures of vegetation greenness and damage from optical remote sensing, focused on events in the central United States.