Hybrid-Pol Based Three-Component Scattering Model for Analysis of RISAT Data

In this paper, we present an unsupervised model-based decomposition technique for the analysis of hybrid-pol datasets. The proposed approach develops a hybrid-pol version of full-pol three-component scattering model by deriving all decomposition parameters in terms of the hybrid-pol Stokes parameters. By using these decomposition parameters, the contribution of three basic scattering mechanisms, namely surface-scattering from Bragg surface region, dihedral-scattering from urban region and volume-scattering from forest region, are estimated. The decomposition parameters take surface dielectric properties under consideration that makes the proposed method suitable to provide more realistic representation of the Earth's surface. To estimate the efficacy of the proposed technique, the hybrid-pol data acquired over Mumbai city using ISRO's RISAT-1 satellite is used. For comparative analysis, the proposed technique is compared with the conventional decomposition techniques, such as m - δ, m - α̇, and modified m - χ.