Analysis of Polarimetric-Dependent InSAR Coherence Modulation Arising from Deep Electromagnetic Ground Penetration

Abstract:
We examine cross-pol InSAR “volumetric" coherence behavior due to multiple-scatter, and the induced multiplicity of “similar", reciprocal backscatter mechanisms. Our results are as follows. First, the cross-pol volumetric coherence’s unwrapped phase grows identically to co-pol volumetric coherence unwrapped phase in the strong subsurface wave guidance regime. Second, unlike co-pol volumetric correlation’s inverse proportionality to InSAR baseline in this regime, said multiplicity can cause cross-pol volumetric correlation to degrade faster (inverse quadratic) versus baseline. Summarizing, the cross-pol and co-pol volumetric coherences can exhibit very different sensitivities to subsurface scatter, encouraging their combined exploitation for remote sensing of layered, penetrable media.