摘要
针对场地辐射定标方法难以覆盖遥感器动态范围的问题,提出基于多种反射率呈线性的宽动态目标的高分辨率光学卫星相机在轨辐射定标方法。以地面同步的实际测量代替气溶胶散射特性假设,采用线性回归法分离宽动态目标反射辐射与程辐射、地-气耦合辐射及暗电流等背景辐射,在简化辐射传输计算的同时降低对背景环境的要求,实现星载高分辨率遥感器全动态范围定标与响应线性检测。试验结果表明:光学卫星相机基于宽动态目标的在轨辐射定标方法的不确定度小于3.6%,与反射率基法定标结果之间的差异小于5.5%,反演的地物反射率及辐亮度与实测值之间的误差均小于6%,验证了在轨辐射定标方法的有效性,该方法可以满足复杂环境条件下高精度在轨定标的应用需求。
Aiming at site radiometric calibration is difficult to cover the dynamic range of the remote sensor, an on-orbit calibration method for high-resolution optical satellite camera is presented using wide dynamic targets with multiple linear reflectance(WDTMLR). It replaces the assumption of aerosol scattering characteristics with the actual measurement of ground synchronization. At the same time, the WDTMLR approach could isolate the response of wide dynamic targets from the response produced by sky path radiance, ground-atmospheric coupled radiance and dark current by using linear regression method, which simplifies radiometric transfer calculation and reduces the requirement of background. The WDTMLR method can achieve full dynamic calibration and linear measurement of spaceborne high-resolution remote sensing sensor. Results show that the uncertainty of the calibration approach is less than 3.6%. The difference in calibration coefficient between the WDTMLR method and the reflectance-based method is less than 5.5%. Moreover, the difference between the reflectivity and radiance of ground object obtained by the satellite sensor and that of field measured value is less than 6%, which demonstrate the effectiveness of on-orbit radiometric calibration. The WDTMLR method can satisfy with the application requirements for high-precision on-orbit calibration in complex environmental conditions.
作者
徐伟伟
张黎明
李鑫
杨宝云
Xu Weiwei;Zhang Liming;Li Xin;Yang Baoyun(Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei,Anhui 230031,China;Key Laboratory of Optical Calibration and Characterization,Chinese Academy of Sciences,Hefei,Anhui 230031,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2019年第10期310-317,共8页
Acta Optica Sinica
基金
国家自然科学基金(41601388)
十三五航天预研基金(GFZX0401430407)
关键词
遥感
辐射定标
宽动态目标
漫射辐射/总辐射比
remote sensing
radiometric calibration
wide dynamic targets
diffuse-to-global ratio
