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中巴资源卫星(简称CBERS卫星)01/02卫星搭载的CCD相机作为主要的有效载荷,采用推扫式成像方式,具有较高的空间分辨率和光谱分辨率．由于在实验室未能采集CBERS-01卫星CCD相机整星对接数据,CCD内定标系统又与对地成像状态存在一定的差别,CBERS-01卫星发射升空之后,CCD图像相对辐射校正中遇到一系列的问题．采用本景图像统计方法和直方图匹配法两种方法进行地面处理,实验证明直方图匹配法可以选择不同时相的CCD图像进行直方图统计生成对照查找表,既可较大程度减轻相机响应的不稳定带来的影响,又可从根本上克服CCD相机非线性特性,因而明显优于本景图像统计方法．鉴于CBERS-01卫星存在的问题,在CBERS-02卫星发射之前,针对CCD相机作了大量的定标实验,并使用半积分球在整星状态下进行对接实验,采集了相对稳定的实验数据,形成一套基础的实验室相对辐射定标系数．CBERS-02卫星在轨飞行时,利用实验室定标系数校正CCD图像,发现图像的相对辐射校正效果仍然不够理想,集中表现在CCD图像3片线阵存在的响应差异,初步研究认为是CCD相机底电平不稳造成的．提出采用统计方法,以中间线阵为基准,通过寻找相邻近似的地物,探测线阵响应之间的差别,进而对其它两线阵的偏移值进行补偿,在不损害图像纹理的情况下,去除3片线阵的响应差异,实验证明该方法具有较好的普适性．
China Resources Pakistan Satellite (referred to as CBERS satellite) 01/02 CCD camera equipped with satellite as the main payload, the use of push-broom imaging, with high spatial resolution and spectral resolution. Due to the failure to acquire the satellite docking data of the CBERS-01 satellite CCD camera in the laboratory, there is a certain difference between the calibration system in the CCD and the imaging state to the ground. After the launch of the CBERS-01 satellite, the CCD image relative radiation calibration is encountered A series of questions. Two methods, the background image statistical method and the histogram matching method, are used to carry out the ground processing. Experiments show that the histogram matching method can select the CCD images from different phases to generate the control look-up table by histogram statistics, which can greatly reduce the camera response The impact of instability, but also fundamentally overcome the non-linear CCD camera features, which is significantly better than the background image statistical methods. In view of the existing problems of CBERS-01 satellite, a large number of calibration experiments were performed on CCD cameras prior to the launch of CBERS-02 satellite. The semi-integrating sphere was used to conduct docking experiments under the condition of whole-star, and relatively stable experimental data were collected. Form a set of laboratory relative radiometric calibration coefficients. When using CBERS-02 satellite orbit calibration, calibration of CCD images by laboratory calibration coefficients shows that the relative radiometric correction effect of the image is still not satisfactory. The difference is mainly reflected in the response differences of the three linear arrays of CCD images. The preliminary study shows that the CCD camera The end of the level caused by instability. A statistical method is proposed to detect the difference between the responses of the linear arrays by searching for the adjacent similar objects based on the intermediate linear array, so as to compensate the offset values of the other two linear arrays. Without damaging the image texture , The response difference of the three linear arrays is removed, and the experiment proves that the method has good universality.