Application of Flood Disaster Monitoring Based on Dual Polarization of Gaofen-3 SAR Image

As China's first civilian high-resolution Polarimetric Synthetic Aperture Radar(PolSAR) imaging satellite, Gaofen-3(GF-3) can provide more abundant feature information for ground targets, which has a wide range of applications in water body extraction, shoreline identification, and flood disaster monitoring. This paper uses the data of the Gaofen-3 dual-polarization satellite to construct a polarized false-color composite orthoimage, polarized water body index, and terrain slope element information, which are applied to the research of object-oriented water body information extraction technology. Compared with traditional single-polarization radar, it not only improves the accuracy of water extraction (Kappa value up to 0.952), but also effectively suppresses the interference of hill shadows. The demonstration of flood disaster monitoring application in the waters of Poyang Lake in Jiangxi Province on July 2020 was carried out, which has shown that the dual-polarization Gaofen-3 has better flood disaster application ability, and can provide important data support and decision-making assistance for emergency disaster reduction departments.