环境二号卫星多光谱图像的薄云检测及去除  

Detection and removal of thin clouds in multispectral images of HJ-2A/B

作　　者：郭庭威 黄红莲 孙晓兵 刘晓 提汝芳 GUO Tingwei;HUANG Honglian;SUN Xiaobing;LIU Xiao;TI Rufang(Key Laboratory of Optical Calibration and Characterization,Anhui Institute of Optics and Fine Mechanics,HFIPS,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院合肥物质科学研究院安徽光学精密机械研究所,中国科学院通用光学定标与表征技术重点实验室,安徽合肥230031 [2]中国科学技术大学,安徽合肥230026

出　　处：《大气与环境光学学报》2023年第4期383-400,共18页Journal of Atmospheric and Environmental Optics

基　　金：高分重大专项(30_Y20A010_9007_17/18)。

摘　　要：在遥感图像中,大面积的薄云会使得地物信息被遮蔽,从而对后续图像的判读以及应用产生极大的影响。为消除卫星图像中薄云对下垫面的影响,开发了针对多光谱图像的薄云检测与去除算法。该算法首先利用蓝绿波段合成外推波段,通过暗像元搜索,生成薄云厚度图(HTM)和薄云掩膜图,进而得到无云区像元与云区像元;再计算图像每个波段的HTM,利用外推波段的HTM与每个波段的HTM求得每个波段的线性回归系数,由该系数对图像进行薄云去除。将该方法应用于环境减灾二号(HJ-2A/B)卫星的多光谱图像,研究结果表明,对不同地表类型,薄云去除后图像质量均得到明显的提升,能够清晰地展现出薄云下覆盖的地物信息,并且不影响无云区域的图像质量。利用该算法进行薄云去除后,卫星多光谱图像的清晰度、对比度和标准差都有显著的提升,为后续图像应用提供了质量保障。In remote sensing images,large areas of thin clouds can obscure ground object information,which has a great impact on subsequent interpretation and application of the images.In order to eliminate the influence of thin clouds on the underlying surface in satellite images,an algorithm for thin cloud detection and removal in multispectral images is developed.In the algorithm,the blue-green bands is used to synthesize extrapolated bands firstly,and then cloud thickness map(HTM)and thin cloud mask map are generated through dark pixelsearch,thereby obtaining cloud-free area pixel and cloud area pixel.Secondly,the HTM of each band is calculated,then both of the HTM of the extrapolated band and the HTM of each band are used to obtain the linear regression coefficient of each band.Finally,the images are subjected to thin cloud removal based on the coefficients.The method is applied to the multispectral images of Huanjing Jianzai-2A/B(HJ-2A/B)satellites.The results show that for different surface types,the image quality is significantly improved after removing thin clouds,and the ground object information covered by thin clouds can be clearly displayed,without affecting the image quality of cloud-free areas at the same time.After using this algorithm to remove thin clouds,the clarity,contrast and standard deviation of the multispectral images can be significantly improved,which provides quality assurance for subsequent image applications.

关 键 词：遥感影像 薄云去除 云检测 薄云厚度图 环境减灾二号卫星 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置]