摘要
针对我国光学遥感卫星高频次和高精度定标的技术需求,以及目前人工定标的不足,研制了超光谱比值辐射仪系统.该仪器具备长期自动观测功能,光谱范围为400～2 500nm.光机系统主要由前置光学系统和光谱模块组成.根据场地定标中的参数需求与自动化定标的目标,设计积分球测量总辐照度,并通过遮挡的方式实现漫射辐照度的测量,获得卫星定标中的漫总比数据;设计光学镜头测量地面辐亮度,从而实现大气-地表辐射特性的自动观测.同时仪器集成了定标数据实时预处理和远程传送等功能.为验证仪器的野外环境适应性和自动化测量数据的可靠性,与传统人工测量地表反射率与漫总比的方式进行了外场对比实验.实验结果表明,两种方式所测的总辐照度、漫射辐照度和直射辐照度的相对偏差均小于5%,漫总比的绝对偏差均小于0.025%;所测反射率整体趋势相同,且二者的偏差普遍在±1%以内,最大偏差小于±2.5%.超光谱比值辐射仪具有较高的自动化测量精度,能够替代人工测量大气辐射特性参数和地表反射率,实现较高的测量频次,在遥感卫星自动化定标领域具有广阔的应用前景.
Aiming at the technical requirements of high-frequency and high-precision calibration of optical remote sensing satellites in China, and the current shortage of manual calibration, a hyperspectral ratio radiometer system was developed. The instrument has long-term automatic observation function with a spectral range of 400~2 500 nm. The optomechanical system consists mainly of a front optical system and a spectral module. According to the parameter requirements in the site calibration and the target of automatic calibration, the instrument designs the integrating sphere to measure the total irradiance, and realizes the measurement of the diffuse irradiance by occlusion, and obtains the diffuse ratio data in the satellite calibration. Designing optical lenses to achieve ground radiance measurements for automatic observation of atmospheric-surface radiation characteristics. At the same time, the instrument integrates real-time pre-processing and remote transmission of calibration data. In order to verify the field environment adaptability of the instrument and the reliability of the automated measurement data, an external field comparison experiment was conducted with the traditional method of manually measuring the surface reflectance and the diffuse ratio. The experimental results show that the relative deviations of the total irradiance, diffuse irradiance and direct irradiance measured by the two methods are less than 5%, and the absolute deviation of the diffuse total ratio is less than 0.025%;the overall trend of the measured reflectivity the same, and the deviation of the two is generally within ±1%, the maximum deviation is less than ±2.5%. The hyperspectral ratio radiometer has high automatic measurement accuracy, can replace the artificial measurement of atmospheric radiation characteristic parameters and surface reflectance, and achieve higher measurement frequency. It has broad prospects in the field of remote sensing satellite automatic calibration.
作者
张权
李新
刘恩超
张艳娜
翟文超
郑小兵
ZHANG Quan;LI Xin;LIU En-chao;ZHANG Yan-na;ZHAI Wen-chao;ZHENG Xiao-bing(Key Laboratory of Optical Calibration and Characterization, Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences, Hefei 230031, China;University of Science and Technology of China, Hefei 230026, China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2019年第3期102-112,共11页
Acta Photonica Sinica
基金
十三五航天预研项目(No.D040401)
国家自然科学基金青年项目(No.41705013)
国家自然科学基金(No.61505222)~~
关键词
辐射定标
反射率
辐照度
漫总比
光机设计
Radiometric calibration
Reflectivity
Irradiance
Diffuse-to-global ratio
Opto-mechanical design
