目前航天遥感相机还不能预先获取场景光谱辐射信息, 也就不能根据场景内容调整曝光参数。为此, 提出一种“测光、解算、成像”的自适应调整曝光参数方法。为减轻测光相机实际应用时对航天遥感相机重量的影响, 提出了应用大尺度测光相机进行测光, 并提出了依据低分辨图像指导高分辨率成像的方法。首先, 对典型场景曝光统计特征随尺度的变化规律进行统计; 其次, 利用大尺度测光图像进行尺度合并, 并计算各尺度下的曝光时间; 然后, 通过多项式拟合建立尺度与曝光时间之间的函数关系, 进而确定原尺度对应的曝光参数, 从而实现用大尺度测光相机指导航天遥感相机成像。无人机数据结果表明, 该方法适用于各种典型场景, 且利用大尺度拟合确定的曝光参数与用原尺度图像确定的曝光参数误差小于4%。卫星照片数据表明, 测光尺度比超过90倍时, 利用大尺度拟合确定的曝光参数与用原尺度图像确定的曝光参数误差小于6%, 仍能够准确指导高分辨相机成像。

At present, the space remote sensing camera still can not obtain the scene spectral radiance information in advance, so it can not adjust the exposure parameters according to the scene content. To this end, a method for adaptively configuring exposure parameters is proposed, which is realized by metering, calculating and imaging. In order to reduce the influence of metering camera on space remote sensing camera weight in practical application, the paper presents the application of a large-scale metering camera for metering, and a method of high resolution imaging based on low resolution image is proposed. Firstly, the change rule between the statistical characteristics of exposure of typical scenes and the scale. Large-scale metering image is used to conduct scale merging, and the exposure time of each scale is calculated. The function relationship between scale and exposure time is established by polynomial fitting, and the exposure parameters corresponding to the original scale are determined, so as to realize the imaging of space remote sensing camera with large-scale metering camera. According to the statistical results of unmanned aerial vehicle, the method can be applied to several typical scenes, the exposure parameter error between the value determined by large-scale fitting and the value determined by original scale image is less than 4%. Satellite picture data show that the error between the exposure parameters determined by large-scale fitting and the exposure parameters determined by the original scale image is less than 6% when the metering scale ratio is more than 90 times, but it still can accurately guide high-resolution camera imaging.