Properties of light reflected from road signs in active imaging for driving safety

摘要

Nisihl-vision systems in vehicles are a new emerging technology. A crucial problem in active (illumination-bascil) systems is distortion of images by saturation and blooming, due to strong retro-reflections from road signs, In this work we quantified this phenomenon. We measured the Mueller matrices and the polarization state of the reflected light from three different types of road signs commonly used Measurements of the reflected intensity were taken also with respect to the angle of reflection. We found that different types of signs have different reflection properties. It is concluded from our measurements that the optimal solution for attenuating the retro-reflected intensity is using a linear lu>ri/Dntal polarized light source and a linear vertical polarizer Unfortunately, while the performance of this solution is for two types of road signs, it is less efficient for the third sign type.