在轨完成CCD非均匀性校正的方法

摘要

为使空间遥感相机图像具有良好的均匀性,利用XQ2VP40 FPGA在轨实时完成TDI-CCD非均匀性校正.首先对CCD非均匀性校正原理进行分析,提出了半饱和灰度值和暗场灰度值的两点校正法;然后,介绍了空间遥感相机的系统结构,利用FPGA实现了校正算法;最后,通过实验对均匀性校正的有效性进行了验证.实验结果证明:FPGA在轨实时完成CCD非均匀性校正的方法是可行的,对于非均匀性5%的TDI-CCD,校正后非均匀性控制在1%以内.%In order to get space camera image with good uniformity, a method of real-time TDI-CCD non-uniformity correction in orbit using XQ2VP40 FPGA is studied.Firstly the principle of CCD non-uniformity correction is analyzed, a two-point correction algorithm of half saturation gray and dark field gray is proposed, then the architecture of space cameras is introduced and correction algorithm utilizing FPGA is realized, finally the effect is proved by experimental result.The experimental results show that the method of CCD non-uniformity correcting is feasible, for the TDI-CCD whose non-uniformity is 5％, the non-uniformity is less than 1 ％ after correction.