云相机相对辐射定标技术研究  

Relative Radiometric Calibration Technique of Cloud Camera

作　　者：汪杰君[1] 池杲鋆 李孟凡 王相京 胡亚东[2,3] 厉卓然 洪津 Wang Jiejun;Chi Gaojun;Li Mengfan;Wang Xiangjing;Hu Yadong;Li Zhuoran;Hong Jin(School of Electronic Engineering and Automation,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China;Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Sciences,Chinese Academy of Sciences,Hefei 230031,Anhui,China;Key Laboratory of Optical Calibration and Characterization,Chinese Academy of Sciences,Hefei 230031,Anhui,China)

机构地区：[1]桂林电子科技大学电子工程与自动化学院,广西桂林541004 [2]中国科学院合肥物质科学研究院安徽光学精密机械研究所,安徽合肥230031 [3]中国科学院通用光学定标与表征技术重点实验室,安徽合肥230031

出　　处：《激光与光电子学进展》2023年第9期245-254,共10页Laser & Optoelectronics Progress

基　　金：王宽诚率先人才计划“卢嘉锡国际团队项目”(GJTD2018-15)。

摘　　要：云相机采用阈值法对观测目标区域进行在轨实时云识别。在云判算法中,辐射度量的准确性将会影响最终的反演结果。本文建立了云相机像元响应值与辐亮度之间的信息模型,针对云相机探测器各像元在入射光均匀一致时,输出响应值出现不相等的情况提出了改进措施。首先,根据云相机的信息模型分析了探测器像元响应值不同的原因,建立了云相机的相对辐射定标模型。然后,由于云相机视场角较大,大口径积分球辐射源出射光也难以一次性覆盖所有视场,在实验中设计了分视场测试的方式。最后,根据相对辐射定标模型和分视场测量方式,进行了云相机的相对辐射定标。实验结果表明:云相机对积分球成像结果校正前非均匀性为6%左右,经相对辐射定标校正后,在轨典型信噪比条件下非均匀性达到1.5%以内,低信噪比条件下达到3.25%。定标测试结果满足云相机设计的指标要求。The cloud camera adopts the threshold method to detect cloud distribution information in the observation target area.In the cloud judgment algorithm,the accuracy of the radiance will affect the final inversion result.An information model between the response value of the pixel and the radiance was established.Improvement measures are proposed for the situation where the output response values of each pixel of the cloud camera are unequal when the incident light is uniform.First,according to the information model,the reasons for the different response values of the detector were analyzed,and the relative radiometric calibration model was established.It is difficult for the light emitted by the largediameter integrating sphere radiation source to cover all the fields of view simultaneously due to the large field of the cloud detection camera.Therefore,a subfield of view measurement method was designed.The relative radiometric calibration of the cloud camera was performed using the calibration model and the subfield of view measurement method.The experimental results indicate that the nonuniformity of the imaging results of the integrating sphere is approximately 6%before correction.After the relative radiometric calibration correction,the nonuniformity is less than 1.5%under a typical signalnoiseratio(SNR)and approximately 3.25%under a low SNR.The results of the calibration meet the requirements of the design of the cloud camera.

关 键 词：测量 云相机 信息模型 辐射定标 相对定标 分视场测试 

分 类 号：TH74[机械工程—光学工程]