FY-4B GHI长波红外波段的发射前辐射表征和定标  

Prelaunch Radiometric Characterization and Calibration for Long Wave Infrared Band of FY-4B GHI

作　　者：李秀举 曹琦 周树添 钱婧[1,2] 王保勇[1,2] 邹曜璞 王静 沈霞[1,2] 韩昌佩 王利智[1,2] 周宇翔[1,2] 李盼盼 Li Xiuju;Cao Qi;Zhou Shutian;Qian Jing;Wang Baoyong;Zou Yaopu;Wang Jing;Shen Xia;Han Changpei;Wang Lizhi;Zhou Yuxiang;Li Panpan(Key Laboratory of Infrared Detection and Imaging Technology,Chinese Academy of Sciences,Shanghai 200083,China;Shanghai Institute of Technical Physics,Chinese Academy of Sciences,Shanghai 200083,China;National Satellite Meteorological Centre,China Meteorological Administration,Beijing 100081,China)

机构地区：[1]中国科学院红外探测与成像技术重点实验室,上海200083 [2]中国科学院上海技术物理研究所,上海200083 [3]中国气象局国家卫星气象中心,北京100081

出　　处：《光学学报》2023年第12期155-166,共12页Acta Optica Sinica

基　　金：中国科学院青年创新促进会资助项目(2018273)。

摘　　要：静止轨道快速成像仪(GHI)是风云四号B星(FY-4B)的主要有效载荷之一。针对该仪器长波红外波段的大视场、高空间分辨率等特点,提出了相应的发射前辐射定标和表征方法。建立了一套定标系统装置,实现了长波红外波段的发射前辐射定标,定标不确定度优于0.67 K@300 K。测量并研究了长波红外波段的空间噪声特性。根据长波红外焦平面4个线阵的设计特点,提出了两种最佳成像探元选择方法,即基于信噪比最大化和响应信号固定图形噪声最小化的方法。测量并分析了这两种最佳成像探元组合线阵的温度探测灵敏度,均优于任务要求,平均水平达到了50~60 mK@300 K。评估了星上黑体参考标准的精度,星上黑体标称亮温比真实亮温偏低约0.42 K@300 K,该结果对黑体的在轨应用具有重要参考意义。Objective Calibration is the process of describing the parameters needed to understand and quantify the expected application performance of a sensor.In the prelaunch radiometric characterization and calibration,the onorbit environment should be simulated as much as possible,and the tests are performed in a controlled environment using a standard source of known radiation.The measurements made during the prelaunch radiometric calibration are used to verify whether the instrument status is correct,quantify the calibration equation and radiometric measurement model parameters,and estimate the measurement uncertainty.The measurement performance and limitations are determined,and whether the sensor meets the mission requirements are verified.By identifying and characterizing unique sensor performance characteristics,the influence of sensor behavior on expected measurement is minimized.The Geostationary Highspeed Imager(GHI)is one of the main payloads of Fengyun4B(FY4B)satellite,the research in this paper is an important basis of the on orbit quantitative application for long wave infrared(LWIR)band of GHI.Methods The commonly used radiometric calibration methods in the laboratory are the distant small source combined with the collimator method and the near extended source method.The distant small source combined with collimator method is to place the point source blackbody at the focal plane of the collimator to realize the beam expansion and collimation of the calibration beam,so that the calibration beam can fill the instrument's entrance pupil and field of view.The near extended source method can provide a standard calibration source with good stability,uniformity,Lambertian and large aperture,and does not require expensive lowtemperature collimators and accurate collimator calibration parameters.In this paper,the largearea and near extended source blackbody calibration method is used,which can realize the full field of view and full aperture radiometric calibration of GHI.GHI,external blackbody,deep low temperatur

关 键 词：测量 辐射定标 红外成像系统 黑体 光学遥感 静止轨道快速成像仪 风云四号 

分 类 号：TP732.2[自动化与计算机技术—检测技术与自动化装置]