Envisat vs. Sentinel-1 radar

Detail over China’s Poyang lake from the ASAR on Envisat acquired on 14 April 2008 (left) in ‘alternating polarisation’ mode, and from the Sentinel-1A SAR acquired on 12 May 2014 (right) in ‘dual polarisation’ mode. Even though the SAR on Sentinel-1A is still being calibrated, the increased quality of the dual polarisation mode imagery versus the alternating polarisation mode imagery is evident.