推扫型干涉成像光谱仪去除条带非均匀性的方法

Stripe-reduction of the Push-broom Interferential Imaging Spectrometer

分析了推扫型干涉成像光谱仪的结构特点和工作原理,指出了由于加工误差导致入射狭缝的宽度不均匀,使干涉图像沿狭缝方向存在亮度差异,复原后的光谱立方体图像上出现平行于推扫方向的非均匀性条带,影响了光谱立方体的图像质量和光谱精确度.采取校正系数法去除条带,讨论了获取校正系数的方法,并使用仪器的定标干涉数据提取成像面上沿狭缝方向的不均匀特性,获得了校正系数,对干涉图像进行处理以消除条带.结果表明:校正系数法能够去除大部分条带.根据处理后残余条带的情况,在没有在轨定标数据的情况下,使用均匀景物的光谱立方体数据提取不均匀特性,修改了校正系数,有效地消除了残余条带.

The structure and work principle of push-broom interferential imaging spectrometer was analyzed.It was found that the brightness of interferential data was non-uniform along the slit direction by the processed error of slit,the stripe noises along the push-broom direction were added on the restored spectral-image cube,image quality was degraded,and spectral information was difficult to evaluated.The corrected coefficient method was used to reduce stripes,and several coefficient-extracted methods were discussed.The non-uniformity of interferential data was extracted from the calibration of instruments,and the corrected coefficient was multipled by the interferential data to reduce the stripes.The results show that numerous stripes are reduced.Without the on-orbit calibration data,the coefficient is modified by the spectral-image cube contained uniform targets,and the remanent stripes are reduced efficiently by the modified coefficient.