Detection of flooded vegetation and measurements of water level changes using Radarsat-2

A specific double-bounce radar backscattering mechanism observed in C-band Radarsat-2 data is used to measure water level changes in areas of wetland and inundated vegetation. The backscattered SAR signal from the water - vegetation double bounce mechanism is usually much stronger than the backscattered signal from the double bounce from dry surfaces. This is because the smooth water level reflects most of the signal along a preferential direction towards the vegetation canopy, as opposed to the dry ground which scatters the signal in multiple direction. As an effect, the SAR amplitude is stronger than the one related to dry vegetation and the interferometric phase maintains coherence in time, making possible accurate phase measurements related to water level changes.