大视场空间相机CCD性能测试及筛选方法

Method of CCD test and screening for space camera with wide field of view

空间相机使用CCD拼接技术组成长焦平面,可有效地增加空间相机的视场和幅宽。拼接CCD之间的性能差异会影响空间相机的成像质量,为了在大视场空间相机研制时挑选高性能且性能一致的CCD,提出了一种大视场空间相机CCD性能测试与筛选方法。首先,介绍了CCD的成像电路设计、以及CCD光谱特性和辐射特性的测试方法。然后,介绍了CCD的筛选流程,第一步是从各CCD裸片的几何特性、信噪比、相对光谱响应、响应非均匀性、非线性、暗电流以及动态范围等角度进行筛选,将不满足指标的CCD剔除,第二步是依据辐射响应一致性筛选出满足要求的CCD,通过数据分析比较得出饱和辐照度筛选法优于响应度筛选法。最后,采用饱和辐照度筛选法从10片CCD中筛选出饱和辐照度一致性最好的4片CCD,饱和辐照度相对偏差为0.23%,该组CCD已经被应用于某大视场空间相机的研制,并获得了良好的效果。

CCD mosaic technology can effectively increase space camera′s field of view and image width. CCD′s performance difference will decrease space camera′s image quality. In order to screen the same high-performance CCDs for wide field of view space camera, a method of CCD test and screening was proposed. Firstly, the design of CCD′s imaging circuit and the test method of CCD′s spectral and radiant characteristics were introduced. Then, the screening process of the CCD was introduced, the first step was screening CCD on the basis of the geometry characteristics, signal-to-noise ratio, relative spectral responsivity, photo response non-uniformity, non-uniformity, non-linearity, dark current, and dynamic range, then the poor-performance CCD would be removed. Secondly, the CCD on basis of radiant response consistency was screened. And data analysis shows consistency screening method of saturation irradiance is better than consistency screening method of responsivity. Finally, the most consistent four CCDs was screened from ten CCDs by consistency screening method of saturation irradiance, whose saturation irradiances′ relative deviation was 0.23%. The screened four CCDs has been used in a wide field of view space camera, which received wonderful results.