In this paper a quasi mono-static, quad-polarized imaging system for short-range UWB-Radar is presented. The Pauli scattering matrix decomposition is applied onto the gathered Radar data to break down the polarimetric backscattering signature into a sum of elementary scattering contributions. Subsequently a simple but innovative single bounce ↔ double bounce dominance criterion is applied which successfully classifies image segments according to occurring scattering mechanisms. Novel wideband antennas with high polarization purity and equal phase centres in both polarizations are introduced. Experimental Validation is carried out with a pair of these antennas and an M-sequence Radar device.