The China Brazil Earth Resources Satellite (CBERS) ended the dependence on foreign satellites. Along with the series of CBERS and the enhancement of satellite applications, it is necessary to search correlative data p...The China Brazil Earth Resources Satellite (CBERS) ended the dependence on foreign satellites. Along with the series of CBERS and the enhancement of satellite applications, it is necessary to search correlative data processing methods. Because cloud appears in the atmosphere, an image with clear sky conditions is often hard to obtain. How to remove cloud is an important sector of increasing image quality. An improved homomorphism filtering method is adopted to remove thin cloud qualitatively at first, and all bands are selected to classify pixels. Based on the fact that visible band images contain more aerosol effects than infrared bands, visible bands are used to determine clear or hazy regions and the reflectances of different surface classes in clear regions are calculated. At last the mean reflectance of the same classes in clear and hazy regions is matched to remove cloud. The image visual effect is improved; meanwhile, the ground reflectance is retrieved to meet the needs of remote sensing quantification.展开更多
基于高分辨率图像对比法,利用同一卫星平台上空间分辨率19.5m的CCD相机图像对CBERS-02B卫星上空间分辨率为258m的WFI成像仪图像进行在轨MTF(modulate transfer function)测量,获得WFI(wide field imager)相机沿轨、跨轨与45o方向的MTF曲...基于高分辨率图像对比法,利用同一卫星平台上空间分辨率19.5m的CCD相机图像对CBERS-02B卫星上空间分辨率为258m的WFI成像仪图像进行在轨MTF(modulate transfer function)测量,获得WFI(wide field imager)相机沿轨、跨轨与45o方向的MTF曲线,并计算出3个方向的线扩展函数LSF(line spread function),获得3个方向的有效半带宽。结果表明WFI相机红波段跨轨、沿轨与45o方向的有效半带宽,即有效瞬时视场,分别为1.188,1.165与1.281个像元,近红外波段为1.258,1.195与1.326个像元。基于获得的MTF,利用维纳滤波法对WFI图像进行补偿,部分恢复了WFI图像的细部信息。展开更多
文摘The China Brazil Earth Resources Satellite (CBERS) ended the dependence on foreign satellites. Along with the series of CBERS and the enhancement of satellite applications, it is necessary to search correlative data processing methods. Because cloud appears in the atmosphere, an image with clear sky conditions is often hard to obtain. How to remove cloud is an important sector of increasing image quality. An improved homomorphism filtering method is adopted to remove thin cloud qualitatively at first, and all bands are selected to classify pixels. Based on the fact that visible band images contain more aerosol effects than infrared bands, visible bands are used to determine clear or hazy regions and the reflectances of different surface classes in clear regions are calculated. At last the mean reflectance of the same classes in clear and hazy regions is matched to remove cloud. The image visual effect is improved; meanwhile, the ground reflectance is retrieved to meet the needs of remote sensing quantification.
文摘基于高分辨率图像对比法,利用同一卫星平台上空间分辨率19.5m的CCD相机图像对CBERS-02B卫星上空间分辨率为258m的WFI成像仪图像进行在轨MTF(modulate transfer function)测量,获得WFI(wide field imager)相机沿轨、跨轨与45o方向的MTF曲线,并计算出3个方向的线扩展函数LSF(line spread function),获得3个方向的有效半带宽。结果表明WFI相机红波段跨轨、沿轨与45o方向的有效半带宽,即有效瞬时视场,分别为1.188,1.165与1.281个像元,近红外波段为1.258,1.195与1.326个像元。基于获得的MTF,利用维纳滤波法对WFI图像进行补偿,部分恢复了WFI图像的细部信息。
