海洋一号D卫星海岸带成像仪偏航90°相对辐射定标  

A study on relative radiometric calibration using side-slither data for HY-1D CZI

作　　者：陈儒 韩静雨 王密[1] 何鲁晓 戴荣凡 孙从容[2] CHEN Ru;HAN Jingyu;WANG Mi;HE Luxiao;DAI Rongfan;SUN Congrong(State Key Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing Wuhan University,Wuhan 430079,China;National Satellite Ocean Application Service,Beijing 100081,China;School of Cyber Science and Engineering,Wuhan University,Wuhan 430079,China)

机构地区：[1]武汉大学测绘遥感信息工程国家重点实验室,武汉430079 [2]国家卫星海洋应用中心,北京100081 [3]武汉大学国家网络安全学院,武汉430079

出　　处：《遥感学报》2023年第1期43-54,共12页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家重点研发计划(编号:2021YFC2803300);湖北省自然科学基金(编号:2020CFA001)。

摘　　要：海洋一号D(HY-1D)卫星搭载了一台海岸带成像仪CZI(Coastal Zone Imager),由两台三反离轴相机组成,成像仪同时采用了视场拼接和光学拼接两种拼接方式。由于CZI高达63°的视场角,相机边缘畸变明显,其所成偏航90°影像存在明显的非线性畸变。本文针对HY-1D卫星海岸带成像仪的结构特点,提出了一种基于探元邻接关系的偏航数据自动标准化方法,有效地改善了海洋一号海岸带成像仪偏航图像非线性畸变的问题,保证了线阵电荷耦合器件CCD(Charged Coupled Device)探元对同一地物成像的理论前提。利用HY-1D海岸带成像仪偏航90°辐射定标数据计算获得相机相对辐射定标系数,对卫星正常推扫影像进行相对辐射定标实验,并利用在轨统计法进行对比实验。使用本文方法利用偏航辐射定标数据进行相对辐射定标后,陆地场景下传感器所有探元最大条纹系数优于0.33%,平均条纹系数优于0.04%,中位数条纹系数优于0.03%;海洋场景下传感器所有探元最大条纹系数优于0.48%,平均条纹系数优于0.07%,中位数条纹系数优于0.06%,各项指标均优于基于大量数据统计的在轨统计法。实验结果表明本文方法有效地提高了HY-1D卫星海岸带成像仪影像的相对辐射定标质量。The HY-1D satellite is equipped with a Coastal Zone Imager(CZI), which uses both field-of-view-butting and optical-butting.Due to the CZI’s super large 63° field of view, the edge of the camera is distorted obviously, which makes the side-slither images distorted observably nonlinearly. The Lines on side-slither images are not slanted lines close to 45°, but irregular curves with a straight middle and bent edges. The traditional processing algorithm for side-slither images based on LSD(Line Segment Detector) is not suitable for the side-slither image of the HY-1D CZI. Aiming at the structural characteristics of the HY-1D CZI, this paper proposed a method for automatic standardization of side-slither images based on the neighbor relationship of detectors, which effectively resolves the problem of the nonlinear distortion of the HY-1D CZI’s 90 degree side-slither image. Firstly, primary correction is performed on the side-slither image according to the traditional side-slither image processing method;Secondly, starting from the first column of the primary corrected image,the mean square error between the current column and the next column with a sliding window with a certain step size in the row direction is calculated, and the step corresponding to the minimum mean square error is taken as the relative value of the next column. Based on the offset of the current column, the overall offset of each column is determined in turn;Finally, according to the offset calculated in the second step, the enhanced corrected side-slither image is obtained by adjusting the primary corrected image, and then the relative radiometric calibration coefficient of the camera is obtained through histogram matching on images. The relative radiometric calibration experiments are carried out on the normal push-broom images, and the comparison experiments are implemented using the on-orbit statistical method. After using the method we proposed, for land scenes, the maximum streaking coefficient of all sensors in the land scene is small

关 键 词：偏航定标数据 HY-1D 海岸带成像仪(CZI) 自动标准化处理 相对辐射定标 

分 类 号：P2[天文地球—测绘科学与技术]