Backscattering response of different land cover types in the Lago Grande de Curuai floodplain (Amazon, Brazil) determined from Radarsat-2 and TerraSAR-X data
We analyzed the radiometric responses of main vegetation groups and other classes of interest at the Lago Grande de Curuai floodplain, in the Brazilian Amazon, to determine the influence of several radar imaging parameters (incidence angle, wavelength, spatial resolution and polarization) on the backscattering. Overall, images from the Radarsat-2 sensor, from the S1 imaging mode were the most effective to differentiate the analyzed cover types, mainly due to its greater target penetration capability in relation to TerraSAR-X images. Images with higher spatial resolution showed good potential to characterize local variations in target structure, while HH, VV and HV polarizations had smaller differences in their response variability, with HH polarization showing the largest responses magnitudes. Changes in incidence angle did not significantly affect target differentiation, except in the case of open water surfaces. We also noticed larger variation in target responses related to the time of imaging along the flooding season, evidencing the importance of multitemporal imagery for proper target identification. Overall, Radarsat-2 S1 and TerraSAR-X Stripmap or Spotlight modes offer the most promising capabilities for target discrimination and structure detection in the Amazon floodplain.Pages: 8475-848
