Polarimetric SAR Scattering Characteristics of Steep Terrain

Inhalt:
Polarization orientation angle (POA) is an important parameter of polarimetric radar scattering from slopes in mountainous region. In this paper, we address polarimetric scattering from steep slopes and its relation to POA by adopting a tilted surface model based on Bragg scattering. We have found that, as the azimuthal slope increase, |VV| decreases at a faster rate than |HH|, they become equal, when POA is ±45 degrees, and |HH|>|VV| afterwards. And the cross-pol |HV| does not always increase with azimuth slope, but reaches a maximum then decreases to zero. In addition, we investigate the effect of soil moisture on PolSAR scattering characteristics of steep terrain and the effect of vegetation over surface on POA estimation. The latter is demonstrated with NASA/JPL TOPSAR L-band PolSAR data and C-band InSAR data.