Active Laser Imaging Polarization Properties Of Probing The Experimental Study

The depolarization of a target depends on material and roughness of the target, the wavelength of incident light, the angle of incidence and the characteristics of the instrument(aperture and azimuth angle).when the incidence is linear polarized, because of the difference of the depolarization of target, the degree of polarization of scattering light is different.. So by changing the angle of polarization between two polarimeter, the scattering light of the background can be filtrated, and then the contrast would be improved. In terms of the idea, the method of improving contrast by the technique of polarization imaging is presented. The intensity images and the polarization images of a model of plane in background clutter are obtained. The intensity images and the polarization images of three targets (white paper , lucent flake aluminium and coat of pencil ) are obtained , and when no polarimeter is presented or the angle of polarization are 0°,30°,45°,60°and 90°respectively, the gray levels of the images are calculated by program. Finally , in the different angles, the Mueller coefficient of the model of plane and the painted board are measured.The results show that the contrast of the polarization images is higher than one,s of the intensity images; the technique of polarization imaging can eliminate background clutter by the difference of depolarization of the targets made of the different material, and improve the contrast of images; Mueller coefficient ( )of target is related to the angle of incidence, with increase of the angle of incidence, it decreases firstly ,and then increases , but the curve of Mueller coefficient and the angle of incidence of the target made of different material is different obviously. M11The technique of polarization imaging can be used to measure spectrum of object, detect long-range and dark target, detect target in water and detect atmosphere. Because the laser propagation is influenced by atmospheric turbulence, atmospheric scattering and atmospheric absorption, the application of polarization imaging in detecting long-range object deserve researching deeply.