高分辨率大面阵CCD相机高帧频设计及其非均匀性的校正

High-resolution large area CCD camera frame rate design and its non-uniformity correction

目前采用高分辨率全帧面阵CCD FTF5066M作图像传感器的航拍相机帧频一般不超过1 fps,为了满足高帧频应用,文中首先介绍了全帧型面阵CCDFTF5066M的基本驱动电路,并对其进行了改进,利用CCD 4个输出放大器进行同时输出,使最高帧频达到了3.4 fps,介绍了4路输出时CCD驱动时序、前端处理电路、直流偏置电路、接口电路等的设计,改进后的驱动电路能满足多种航拍相机的应用要求。然后对全帧型面阵CCDFTF5066M的非均匀性进行了分析,并建立了一种响应非均匀性检测系统。利用该系统分别对面阵CCD5066M的4个象限之间的非均匀性和每个像元之间的非均匀性进行了检测。在CCD响应度为线性的基础上,提出了两点校正算法并对非均匀性进行校正。通过校正4个象限响应灵敏度的标准偏差降低到原来的1/13。通过对鉴别率板的重新拍摄,可以看出面阵CCD的非均匀性得到了明显的改善。

Using high-resolution full flame area array CCD FTF5066M as aerial image sensor of the camera, its flame rate is generally not more than 1 fps, which can not meet the high frame rate applications. Firstly, the full flame area array CCDFTFS066M drive circuit was introduced in this paper, and it was also been improved. Using CCD four output amplifiers to output at the same time, the highest frame rate reached 3.4 fps. Secondly, the timing of the CCD driver, front-end processing circuit, DC bias circuit, interface circuit of the four outputs were designed. The improved driver circuit could meet the application requirements of various aerial camera. Then the full flame area array CCDFFFS066M non- uniformity was analyzed, and a non-uniform response detection system was established. Using this system, the array CCDS066M＇s non-uniformity between the four quadrants and each pixel was tested separately. On the basis of CCD linear responsivity, two correction algorithm was proposed to correct the non-uniformity. At last, by correcting, the four quadrants＇s standard deviation of response sensitivity was reduced to the original＇s 1/13. Through the re-shoting of the identify rate board, it can seen that the array CCD＇s non-uniformity has been improved obviously.