基于修正H-α方法的双极化SAR散射机理识别性能分析

Performance Analysis of Scattering Mechanism Identification of Dual-Polarization SAR Using a Modified H-α Decomposition

针对双极化SAR数据修正H-alpha方法,推导得到双极化H-alpha平面有效区域的边界,该边界关于al-pha等于45°轴对称.利用修正H-alpha方法分析HH-VV、HH-HV和HV-VV双极化SAR的散射机理识别性能,给出HH-VV双极化H-alpha平面的一种可行划分方式.理论推导证实,仅HH-VV双极化SAR能区分各向同性表面、偶极子和各向同性二面角散射.NASA/JPL的AIRSAR和DLR的E-SAR数据实验结果表明,HH-VV能基本区分H-alpha平面有效区域内的八种散射机理,而HH-HV和HV-VV仅能区分低熵和高熵散射.

H-alpha decomposition is modified for dual-polarization SAR data applications.The boundary of the feasible region in H-alpha plane for dual-polarization cases is derived.It is different from full polarization that the boundary is symmetrical with respect to alpha being 45 degrees.Performance of scattering mechanism identification is analyzed using the modified H-alpha decomposition for HH-VV,HH-HV,and HV-VV SARs,and a feasible division of HH-VV H-alpha plane is obtained.It is demonstrated theoretically that only HH-VV SAR can distinguish three basic scattering mechanisms from an isotropic surface,a dipole,and an isotropic dihedral.Experimental results using real data,acquired by the NASA/JPL AIRSAR and DLR E-SAR,illustrate that eight scattering mechanisms inside the feasible region in H-alpha plane can be identified on the whole by HH-VV SAR,and only low entropy and high entropy scatterings can be divided by HH-HV and HV-VV SARs.