This paper presents principles and techniques to perform tomographic imaging of volumetric natural environments using Multi-Baseline Polarimetric and Interferometric SAR (MB-POL-inSAR) data. The objective of this work is to provide robust techniques to reconstruct the 3-D structure of media and to estimate some of their physical parameters. The proposed approaches are based on results obtained in [1] on the robust estimation of MB-POL-inSAR quantities, on the POL-INSAR model presented in [2] and on the tomographic techniques introduced in [3] and [4].