采用帧转移CCD的Smear校正通道恢复饱和图像通道的方法研究

Research on Using Frame Transfer CCD Smear Correction Channel to Restore Saturated Image Channels

海洋水色遥感应用对光学遥感仪器提出了高灵敏度与高精度的要求。本文研究的可见近红外成像光谱仪采用推扫扫描的方式,从而获得了较高的灵敏度;通过对系统进行杂散光定标和校正实现高精度测量。杂散光校正算法要求图像中所有目标信号不能饱和。由于仪器的动态范围针对水色目标设置,因而大部分图像通道高亮度的云目标信号会饱和,导致杂散光校正算法无法获得较好效果。以一台基于帧转移面阵CCD的推扫式可见近红外成像光谱仪为研究对象,通过分析系统设置的CCD Smear校正通道的成像机理,论证了在不同光源下Smear通道和各图像通道间均存在线性相关性,进而提出了一种利用Smear校正通道来恢复各图像通道饱和信号的方法,为星上高光谱图像的杂散光校正提供有效的数据源,也为饱和图像恢复提供了一种较为可行的方法。

Ocean color remote sensing applications require optical remote sensing instnmaents with high sensitivity and high precision. The visible and near infrared imaging spectrometer studied in this paper achieved high sensitivity using push-broom scanning, and it achieved high precision measurement by using stray light calibration and correction. Unsaturated target signals in the images are needed when using stray light correction algorithm. The dynamic range of the instruments are set according to ocean color targets, so the signals of high brightness clouds would saturate, and it leads to poor performance of the stray light correction algorithm. This paper works on a push-broom visible near infrared imaging spectrometer based on frame transfer array CCD, and by analyzing the mechanism of the CCD smear correction channel of the system, we prove linear correlation between the image channels and the smear channel under different lights, then we propose a way of restoring saturated signals in image channels using smear correction channel, so it could provide useful data for the stray light correction of the satellite hyperspectral images, and it proposes a feasible way of restoring saturated images.