Research On Target Polarization Characteristics In Various Laser Imaging Methods

The main research content of this paper is the polarization imaging of laser to the target.Lasers play an important role in the fields of optical communication,lidar,remote sensing,aerospace,etc.At the same time,polarized light has received more and more attention due to its unique information recording method,and has great importance in environmental media measurement and target detection.Scientific and practical value.After considering the polarization characteristics,the laser can not only recognize the surface shape and roughness of the target,but also distinguish the difference in the surface material of the target.Usually,the target can also be separated from the background.Therefore,in the laser waveband,the polarization imaging of the target is of great importance.significance.This article first briefly introduces common polarization physical quantities,including Stokes vector and Mueller matrix,and gives the physical meaning of the elements in them.This article summarizes a variety of polarization imaging methods,including Stokes vectorbased imaging methods including polarization imaging,ellipsometry,ellipsometry,and phase difference imaging.In addition,imaging methods based on the Mueller matrix include polarization intensity images,Stokes matrix images,and Mueller matrix images.Combined with the existing polarization imaging method,a multi-angle polarization detection model was established to carry out multi-angle polarization imaging of targets of different shapes,materials and roughness.As a result,it was found that the multi-angle polarization image has a significant advantage in identifying the roughness of the target.The multi-angle ellipsometry images have strong material resolution.Unlike the Stokes vector imaging method,the Mueller matrix-based imaging method can obtain the complete polarization information of the target.The multi-angle polarization intensity image describes all the polarization states of the target through at least 15 effective curves,while the multi-angle Stokes matrix image It contains only 3 effective curves,which are consistent with the multiangle Mueller matrix image.In this paper,different angles of roughness,materials,and square plates with different angles are used to perform multi-angle polarization imaging on them respectively,which illustrates the differences between these polarization imaging methods in roughness identification,material identification,and shape identification.Combined with the imaging model,polarizer,analyzer and other devices are used to modify the lidar to become a polarized lidar.Because the one-dimensional intensity image of the target laser has the ability to identify the shape of the target surface,the polarized lidar and the one-dimensional range image imaging model are combined,and the first imaging method of the polarized one-dimensional range image is proposed.Using the imaging model of polarization distance profile,combined with existing polarization imaging methods,such as polarization degree imaging,ellipsometry,and Mueller matrix image,etc.,this article gives these polarization imaging methods distance information and turns them into distances,respectively.Polarization degree imaging,distance ellipsometry and distance Mueller matrix imaging,so they can obtain the characteristics of the target's polarization information with distance.In this paper,the polarized distance imaging of the slant plate,cone,and sphere shows that the distance polarization degree imaging,distance ellipsometry,and distance Mueller matrix imaging can identify the surface shape,roughness,and material differences of the target.The one-dimensional range intensity image of the target laser has the ability to recognize the shape of the target surface.Therefore,combining the range image with polarization detection,the imaging model of the polarized one-dimensional range image is proposed for the first time.Using the polarization distance profile imaging model,combined with existing polarization imaging methods,such as polarization degree imaging,ellipsometry,and Mueller matrix image,etc.,this article gives these polarization imaging methods distance information and evolves them into distance polarization Degree imaging,distance ellipsometry and distance Mueller matrix imaging,so they can obtain the characteristics of the target's polarization information with distance.In this paper,the polarized distance imaging of slant plate,cone,and sphere shows that distance polarization degree imaging,distance ellipsometry,and distance Mueller matrix imaging have differences in identifying the shape,roughness,and material of the target surface.Finally,the polarized onedimensional distance profile is applied to the target recognition in the grass background.By analyzing the characteristics of the polarized one-dimensional distance profile of the grassland,it is found that the value of the distance ellipsoid angle of the grassland and the value of the M32 element in the Mueller matrix image are much smaller than the ordinary man-made Targets,therefore,the use of distance ellipsometry and distance Mueller matrix images to identify artificial targets in the background of grassland has significant advantages.Finally,the article briefly introduces the advantages of laser inverse synthetic aperture imaging in roughness identification,correlation length identification,shape identification and material identification.This paper also calculates the difference of the same target laser inverse synthetic aperture imaging under different polarized light incidence.The final result shows that +45° linear polarized light and right circular polarized light imaging can obtain a clearer image.