摘要
针对目前“扫描式”反射光场测量系统依赖复杂机械装置、测量效率低以及“照相式”反射光场测量系统测量角度范围小等问题,提出一种基于超广角成像的粗糙面反射光场测量方法。分析了粗糙面反射光场测量原理,优化设计了折反射超广角成像光学系统,实现了天顶角范围0~54°的周视反射光场测量;校准了反射光场测量系统的空间关系与光场强度,校准后反射光场测量最大相对误差为4.12%,周视反射光场测量平均相对误差最大为2.06%;通过模拟Labsphere Permaflect-80漫反射板、WhiteOptics-DF60漫反射板和美国ACA镜面铝板3种粗糙面的反射光场测量结果,证明了所提表面反射光场测量方法的可行性,丰富了粗糙表面反射光场的测量手段,为对材料表面光学反射特性与损伤等的测量、模拟与重构提供了研究基础与技术支撑。
Objective The reflected light field information of a rough surface includes the reflected light angle and intensity,which can be used to retrieve the reflection and morphology characteristics of the surface.Therefore,accurate measurement of the reflected light field has high research value and practical applications in the fields of target detection and recognition,inorbit radiation calibration,material property analysis,optical device stray light analysis,etc.Presently,the traditional"scanning"method uses a mechanical mechanism to achieve pointbypoint scanning measurement of the spatial reflected light field information of the target sample;however,there are problems such as slow measurement efficiency,numerous measurement error links,and poor repeatability.Furthermore,given the influence of incident light wavelength and energy fluctuation on the measured data during the scanning process,the weight gradually increases with increasing time,which may lead to distortion of fullspace BRDF fusion information.In contrast,the emerging"photographic"measurement method based on optical imaging techniques only measures the reflected light field in a small angle range.In this study,to overcome the low efficiency of the"scanning"reflected light field measurement system and the small measuring angle range of the"photographic"reflected light field measurement system,a rough surface reflected light field measurement method based on ultrawideangle imaging is proposed.This method realizes the measurement of multidirectional angle reflected light field information over a large angle range,enriches measurement means of rough surface reflected light fields and is suitable for measuring optical reflection characteristics and damage of material surface.Here,the simulation and reconstruction provide a research basis and technical support.Methods Based on the principle of reflected light field measurement,this paper first determined the overall structure of the reflected light field measurement system,which comprises a light source,sample plate to be measured,a hemispherical reflecting ball screen,and a refractive reflecting ultrawideangle imaging optical system.Next,the catadioptric ultrawideangle imaging optical system was optimized and the best resolution angle in the optical system's field of view was simulated and analyzed.Subsequently,a calibration method for the reflected light field measurement system was studied to realize offaxis spatial position calibration and light field intensity calibration.Finally,the reflected light field measurement results were simulated and analyzed using a Labsphere Permaflect80 diffuse reflector,WhiteOpticsDF60 diffuse reflector,and American ACA specular aluminum plate,proving the feasibility of the proposed surface reflected light field measurement method.Results and Discussions The best resolution angle of the designed reflected light field measurement system is 2°in the range of 0°-54°zenith angle and 15°in the range of 0°-360°azimuth angle(Fig.9).The coordinate distribution of the feature points after calibration was obtained using the offaxis spatial position mapping relationship(Fig.11);the relative error of light field measurement increases with increasing zenith angle.The maximum relative error in the range of the measuring field of view is 4.12%at the zenith angle of 54°and azimuth angle of 255°.The maximum average relative error is 2.06% and the average relative error is less than 1%within the range of 0°-36°zenith angle(Fig.14).The measurement results were obtained using the Labsphere Permaflect80 diffuse reflective plate,WhiteOpticsDF60 diffuse reflective plate,and ACA specular aluminum plate of the United States under conditions of uniform illumination using a 550-nm incident beam with a zenith angle of 40°and azimuth angle of 270°(Fig.16).The results show that the surface of specular aluminum material with rough surfaces have strong specular reflection characteristics,which is consistent with the reflection characteristics of the material itself(Fig.17).Conclusions Based on the principle of ultrawideangle imaging,a reflective light field measurement system has been successfully designed here that achieves a best angle resolution of 15°in the azimuth range of 0°–360°and a best angle resolution of 2°in the zenith range of 0°-54°.After calibration,the maximum average relative error of the circumference under each zenith angle is 2.06%.These results support that the"photographic"method of measuring a reflected light field can also be used to measure a reflected light field in a large angle range using a reasonable optical system design.
作者
段宗涛
张健
张国玉
邹阳阳
牛政杰
赵斌
莫晓旭
运志坤
张建良
郭佳
Duan Zongtao;Zhang Jian;Zhang Guoyu;Zou Yangyang;Niu Zhengjie;Zhao Bin;Mo Xiaoxu;Yun Zhikun;Zhang Jianliang;Guo Jia(School of OptoElectronic Engineering,Changchun University of Science and Technology,Changchun 130022,Jilin,China;Jilin Photoelectric Measurement and Control Instrument Engineering Technology Research Center,Changchun 130022,Jilin,China;Key Laboratory of Optoelectronic Measurement and Control and Optical Information Transmission Technology,Ministry of Education,Changchun 130022,Jilin,China;College of Instrumentation&Electrical Engineering,Jilin University,Changchun 130012,Jilin,China;Air Force Aviation University,Changchun 130022,Jilin,China;Changchun Wanyi Technology Application Co.,Ltd.,Changchun 130022,Jilin,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2023年第11期44-53,共10页
Acta Optica Sinica
基金
吉林省科技发展计划项目(20230201053GX)
国家自然科学基金重大项目(61890960)
长春理工大学科技创新基金(XJJLG-2018-02)。
关键词
双向反射分布函数
超广角成像
反射光场
粗糙表面
bidirectional reflectance distribution function
ultra wideangle imaging
reflected light field
rough surface
