SAR Speckle Characteristics Observed on RADARSAT-2 Dual Polarization Product for Sea

The RADARSAT-2 satellite is Canada's next-generation C-band synthetic aperture radar (SAR) satellite launched in December, 2007. RADARSAT-2 products are characterized by the beam mode used by the satellite and the level of processing that has been applied to the data. This paper examines the speckle characteristics observed on RADARSAT-2 dual polarization products. This work is based on two SLC products acquired in wide swath single beam mode with dual polarization of HH+HV and two SCW products acquired in ScanSAR Wide beam mode with dual polarization of HH+HV, lie in the sea area around Iberian Peninsula, to the southwest (acquired on Sep. 3th, 2009), the east (acquired on Aug. 18th, 2009), the northeast (acquired on Aug. 31st, 2009) and the northwest (acquired on Sep. 3th, 2009) separately of the peninsula. For the SCW products, sub images of different sea area (so with different incident angle) from each of the SAR imagery (both HH and HV) composed a data set. Then the ENLs (Equivalent Number of Looks) are calculated for each sub image, compared with the ENL given by the description of the product. For each sub image, the fitness of the histogram with Gamma as well as Gaussian distribution are tested by chi-square statistical test of χ 2 m. For the SLC products, mean filter processing are carried out to the SLC components to reduce speckle, using different ‘look’ numbers and then the same processing as SCW to find an optimum look number for each speckle model of Gamma and Gaussian distribution. The relationships between ENLs with incident angle and polarization are also investigated in the work. An IDL programme with GUI has been built as a tool for this work.