Comparison of SAR and CYGNSS Surface Water Extent Metrics

Many sensors are suitable for accurate delineation of open water extent, but in vegetated environments, the vegetation canopy can obscure the presence of standing water from detection. Detecting inundation extent in these vegetated environments is especially critical for identifying flooding extent where surface water may exceed flood boundaries and extend into forests surrounding nearby lakes and streams. Regular and timely observations of water surfaces by optical sensors can be impeded by both cloud cover and by vegetation. Here, two microwave techniques for identifying inundation extent will be investigated and compared: L -band global navigation satellite systems reflectometry (GNSS-R) and L - and C -band synthetic aperture radar (SAR); and will confirm that there are correspondences between metrics derived from GNSS reflected signals and L -band SAR to inundated area, including wetlands covered by vegetation.