Wetland Interferometric Synthetic Aperture Radar(InSAR) is a relatively new application of the InSAR technique, which detects water level changes in aquatic environments with emergent vegetation. It provides high spatial resolution hydrological observations of wetland and floodplains that cannot be obtained by any terrestrial-based method. However, InSAR observations are relative both in space and time and, hence, depend on terrestrial (stage) observations for calibration and validation. (from Wdowinski et al, 2006)