The Construction Of Polarized Reflectance Measurement System And The Polarized Reflection Characteristics Of Typical Aluminum Alloys

Polarization is a property of light or electromagnetic radiation and it tends to provide information that is largely uncorrelated with spectral and intensity property.In the field of target detection,polarization information can effectively distinguish the scatterer with differert materials and different surface morphology due to the polarization state of target scattering light is sensitivity to scattering effect and target materials.Comparing with the traditional intensity detection,polarization detection have advantages to improve target contrast and distinguish materials.The measurement and modeling of the optical scattering properties can be used to study the spatial scattering properties for metallic materials,it has important application value in target detection,tracking,recognition and feature extraction.Polarimetric bidirectional reflection distribution function(pBRDF)can effectively contacts the polarization information of incident and reflected light with the physicochemical properties of objects.The study in depth of pBRDF is the most important links of object polarization feature information acquisition and object polarization detection.In this dissertation,the need for characterization of metal target materials in the process of needle polarization detection,the influence of the surface morphology of aluminum alloy materials on the polarization reflection characteristics was studied.which in detail includes:(1)The research of polarization detection of space target and current BRDF and pBRDF models was researched and summarized.BRDF and pBRDF curves were simulated in Matlab,which is the base of next analysis and correction of models;(2)The experiment method was designed and Polarization reflection characteristic measurement system was established.The measurement system includes three major partslight source system,turntable system and control system.The light source system includes a laser light source,a polarizer,and a beam expander system.The turntable system includes a detector and an analyzer.The control system can precisely control the rotation of the turntable through a computer.Using this measurement system can accurately obtain accurate BRDF and pBRDF experimental measurement data at different incident angles and reflection angles.(3)the surface polarization reflection test of 6061-T6,7075-T651 aluminum alloy materials was carried out.Combined with the actual living conditions,The loss of materials in daily life and the processing technology in the process of processing,the experimental material samples were polished,sandblasting,annealing three kinds of treatment,using MATLAB to process the data obtained for each sample material at different angles of incidence Stokes vector and pBRDF matrix elements.According to the experimental results,the polarized reflection characteristics of the aluminum alloy materials and the polarization reflection characteristics of the aluminum alloy materials in different states are obtained.The results show that the polarization reflection characteristics can be used as distinguishing and diagnosing Aluminum alloy based on the state.