信号串扰会对焦平面通道的观测图像产生显著的条纹影响。基于地、月观测数据,对FY-3D核心载荷中分辨率成像光谱仪(MERSI-II)所有通道的串扰效应进行在轨检测并开展了初步的订正实验。检测发现,MERSI-II部分焦平面存在显著的通道信号串扰现象,其中短波红外焦平面通道5,6以及中长波红外焦平面通道20,21,22,23最为显著,分别表现为探元间串扰、通道间串扰两种特征。基于月球点光源成像特性,采用线性近似订正算法计算了串扰系数,并以通道20为例对订正算法进行了初步验证。结果表明,串扰订正可有效移除月球图像的串扰信号并能够显著改善地球观测图像的条纹现象,说明算法具有很好的适用性。

Signal crosstalk can produce significant fringing effects on the observed images in a focal plane channel. Based on the earth and lunar observation data, the on-orbit detection of the crosstalk effects of all bands of the medium resolution spectral imager (MERSI-II) as FY-3D core load, and the preliminary correction tests also done. The detection results indicate that there are significant signal crosstalk phenomena of bands in some MERSI-II focal planes, among which the band 5 and band 6 of short-wave infrared focal plane and the bands 20, 21, 22, and 23 of mid and long wave infrared focal plane are suffered most obviously, manifested as inter-band and inter-detector characteristics, respectively. Based on the lunar point source imaging characteristics, the crosstalk coefficient is calculated using the linear approximation correction algorithm. Moreover, this correction algorithm is preliminarily verified through band 20. The results show that crosstalk correction can effectively remove the crosstalk signals of lunar images and significantly improve the fringe phenomena of earth observation images, implying that the proposed algorithm has good applicability.