全谱段多角度光学成像大气折光误差分析

Atmospheric Refraction Error Analysis for Visual and Infrared Multispectral Sensor in Multi-angle Imaging

星载全谱段成像仪能够同时对可见光、近红外、短波红外、中波红外、长波红外光谱范围内的多个谱段进行探测,在热污染排放检测、农作物长势分析等方面发挥重要作用。然而,当光线穿越大气层时,受大气折射的影响,不同谱段存在程度不一的偏折现象,降低了影像的几何定位精度、谱段间的配准精度,影响全谱段影像的应用效能与价值。针对全谱段多角度成像大气折光误差特性,采用高分五号全谱段光谱成像仪相机参数与大气参数,利用基于椭球分层的光学卫星大气折光改正模型,对全谱段多角度成像在不同区域、不同时间的大气折光误差差异进行了系统性的分析。实验结果表明,当侧摆角为45°时,大气折光引起的蓝波段的绝对几何定位误差约为6.491 m,相对几何定位误差可达2.698 m,对蓝波段与长波红外波段谱段间的配准精度的影响可达0.161 m。

Objectives:The space-borne visual and infrared multispectral sensor(VIMS)can simultaneous-ly detect multiple spectral bands in the visible,near-infrared,short-wave infrared,medium-wave infra-red,and long-wave infrared spectral ranges,which plays an important role in thermal pollution emission detection and crop growth analysis.However,when light passes through the atmosphere,it is affected by atmospheric refraction,which causes different degrees of deflection in different spectral bands.It influences the geometric positioning accuracy of the image and the registration accuracy between the spectral bands,which affects the application of VIMS image.Methods:With VIMS of Gaofen5(GF5),the optical satellite atmospheric refractive correction model based on the measured atmospheric parameters is used to analyze the influence of atmospheric refraction on the geometric accuracy of different bands in different regions and at different times.Results:The experimental results show that when the view angle is 45°,the absolute geometric positioning error of the blue band caused by atmospheric refraction is about 6.491 m,and the rela-tive geometric positioning error is about 2.698 m.The registration accuracy between the blue band and the long-wave infrared band spectrum can reach O0.161 m.Conclusions:This research can provide important support for the data processing of VIMS with higher space resolution.