SAR POLARIMETRIC SIGNATURES FOR URBAN TARGETS – POLARIMETRIC SIGNATURE CALCULATION AND VISUALIZATION
- Faculty of Geomatics & Space Applications, CEPT University, Ahmedabad, Gujarat-380009, India
Keywords: RADARSAT-2, Urban targets, Polarimetric Signatures, Stokes matrix, Copol signature, Crosspol signature
Abstract. Various urban targets (land use) from Ahmedabad city were chosen, followed by generation of polarimetric signatures for each target using the developed tool. These polarimetric signatures were then studied and analyzed in detail. An attempt has been to develop a Polarimetric Signature Calculation and Visual Representation Tool assigned name "POLSIC", to generate Co-polarized and Cross polarized signatures, based on the calculation of Stokes Matrix and the backscattered power at various ellipticity and orientation angles. The input parameters required for the developed tool, are the amplitude and phase values of all the four polarizations, for each target using any quadpol radar imagery. In this study, RADARSAT-2 imagery has been used to obtain the amplitude and phase values of each target, in all four polarization states. Polarimetric signatures were generated for various urban targets using the developed tool. Vegetated land, built up in the city, built up within lake, and road were found to have an overall higher polarimetric response (backscattered power) as compared to grass lawn, fallow land and minimum in case of water body. Such Polarimetric responses were obtained due to factors like surface roughness and orientation of the target with respect to the radar look angle. The shape of the signature also indicates the scattering characteristics.