Surface Normal Vector Estimation From Passive Millimeter-Wave Polarimetric Imaging

Surface normal vector is essential for object recognition and three-dimensional reconstruction. This article establishes a passive millimeter-wave polarization observation model of object thermal radiation. Then, a polarization-based method is proposed to acquire the surface normal vector from multipolarization measurements. The simulation results show that our method has high accuracy and robustness. The outdoor imaging experiment was conducted, and the polarization characteristics of several typical objects in the imaging were analyzed. Experimental results show that our method can successfully estimate the surface normal vector. The possible applications of our method include object recognition and pavement inspection.