GF-5卫星高光谱数据大气校正反射率精度评价

Precision Evaluation on Atmospheric Correction Reflectance of GF-5 Satellite Hyperspectral Data

反射率是高光谱遥感数据应用的基础,直接关系到高光谱应用效能和质量。目前,对国产GF-5卫星高光谱数据的精确大气校正反射率精度评价方法尚未有全面深入的研究,这严重制约了国产高光谱遥感数据的高质量应用。针对此问题,综合采用6S模型和FLAASH模块,选取了三个实验区的三种典型地物及外业光谱数据,采用三种定量化指标进行大气校正,得出了以下结论:三种地物大气校正反射率与实测反射率曲线特征基本一致,黑土地的大气校正反射率光谱最优,水体由于反射率数值较低,大气校正反射率光谱稍差;可见光近红外波段大气校正效果优于短波红外波段;6S模型大气校正结果略优于FLAASH模块,更适用于GF-5卫星高光谱影像。

Reflectance is the basis of the application of hyperspectral remote sensing data,and it is directly related to the efficiency and quality of hyperspectral applications.The accurate atmospheric correction and reflectivity accuracy evaluation methods of domestic GF-5 satellite hyperspectral data have not been fully and deeply studied,which severely restricts the high-quality application of domestic hyperspectral remote sensing data.Aiming at the above problems,this paper uses the 6S model and FLAASH module comprehensively,selects three typical features and their field spectral data in three test areas,uses three quantitative indicators for atmospheric correction,and draws some conclusions:the atmospheric correction reflectance of the three ground objects is basically the same as the measured reflectance curve;the atmospheric correction reflectance spectrum of black soil is the best,and the water body has a lower reflectance value and the atmospheric correction reflectance spectrum is slightly worse;the atmospheric correction effect of the visible near infrared band is better than that of the shortwave infrared band;the atmospheric correction result of 6S model is slightly better than that of the FLAASH module,which is more suitable for GF-5 satellite hyperspectral image.