Comparison of VV and VH Sentinel-1 SAR Imagery in Flood Delineation
Abstract
A change detection and thresholding (CDAT) methodology has been adapted from previous studies to determine flood extent using 2 space borne radar images obtained from Sentinel-1 SAR with one acquired before the flood and another after the flood. Both polarizations available VV and VH have been processed to allow for a comparison of their respective accuracy for delineating surface water and flooded areas. Results have been validated against a Sentinel‐2 optical image, with both polarizations producing total accuracies of 89.0% and 93.8%, with Cohen's kappa coefficient (κ) of 0.778 and 0.799 for VV and VH, respectively. Mapped results are compared to an already generated flood map from the NASA NRT Global Flood Mapping.