一种推帚式高光谱相机非线性相对辐射校正方法

A Non-linear Relative Radiometric Correction Method for Push-broom Hyperspectral

针对推帚式高光谱相机CCD探测元对辐射强度的响应差异而导致采集的光谱影像出现纵向条纹现象,设计一种在轨定标实验方案,提出了直方图匹配结合分段拟合进行相对辐射精校正的方法.将高光谱相机置于可360度旋转的转台上进行多光照条件下、多周期的定标数据采集,并始终保持相机入射狭缝方向与转台运动方向切向平行;依次统计每个谱段单个像元多次采集的灰度直方图和该谱段所有像元的灰度直方图并将二者进行精确匹配;对于可以满足精确匹配条件的灰度级,使用匹配的方法进行相对辐射纠正,对于不能精确匹配的灰度级则通过分段拟合的方法进行精确映射.最后通过实验验证了本算法可以有效地消除光谱影像的纵向条纹,实现光谱影像的相对辐射精确校正.

Since the response of each detector on the Charge Coupled Device（ CCD） of push-broom hyperspectral camera to the same radiant intensity is different,It causes the obvious intensity difference of the collected hyperspectral image,the in-track calibration method is designed and the precise radiometric calibration method is proposed which composes of the histogram matching and piecewise fitting. Put the hyperspectral camera on the tripod to turn around with its vertical central axis about 360o to collect the data under different light conditions. Compute the grayscale histogram of each detector at one spectral band from multi-scans and the histogram of all detectors at same spectral band,If the condition of precise matching between these two histograms is satisfied,the histogram matching method will be adopted,otherwise the piecewise fitting method will be used. The experiment indicates that the algorithm proposed in this paper could eliminate the radial striping and achieve the relative radiometric calibration precisely.