Polarization sensing for target acquisition and mine detection

Previous infrared polarization imaging research has shown manmade objects to be sources of emitted and reflected polarized radiation while natural backgrounds are predominantly unpolarized. The prior work underscored the dramatic improvements in signal to clutter ratio that could be achieved in a typical target acquisition scenario using polarization sensing techniques. Initial investigations into the polarization signatures of surface scattered mines have also shown polarization techniques are able to provide strong cues to mine presence. The US Army Night Vision and Electronics Sensors Directorate has developed complete Stokes imaging polarimeters in the midwave infrared (MWIR, 3-5 µm)1,2, the short wave infrared (SWIR, 1-2 µm) and the visible wavebands in order to investigate polarization phenomenology and to quantify expected improvements to target acquisition and mine detection. This paper will review the designs of the polarization cameras and will summarize efforts to calibrate them. An example phenomenology study of MWIR polarization from surface scattered landmines will be presented.