高频差分采样技术在CCD信号处理中的实现

High frequency difference of sampling technology in CCD signal processing

现在CCD相机已经在很多领域取得了广泛地应用,针对高频CCD模拟视频信号保持时间较短,采样信号速率不高等问题,提出了一种高精度可调、高频差分采样技术。首先,详细阐述了高频模拟视频信号的特性及信号处理中的难点;其次,分析了传统CCD信号处理方法中采样速率不高的原因,在模拟视频输入和采样方式等方面提出了新的改进方法;然后,给出了高精度可调与高频差分采样方法的具体实施,并进行了测试验证;最后,提出了CCD信号处理相关的噪声抑制方法,并对CCD的信噪比性能进行了细致的测试。实验结果表明:改进的CCD信号处理方法使最大采样速率达到80Msps,比传统方法提高了1倍,最小采样精度可以达到0.5ns,而且在最到采样速率下测得的信噪比仍可以达到41.2dB,经过改进的高精度可调与高频差分采样技术提高了CCD图像信噪比,完全满足高频CCD信号处理的应用需求。

CCD camera has now has been widely used in many fields, in view of the high frequency CCD analog video signal holding time is shorter, the sampling signal rate is not high, this paper proposes a high precision adjustable, high frequency difference sampling technology. First, elaborated the characteristics of the high frequency analog video signal and the difficulty in the signal processing; Secondly, this paper analyzes the traditional CCD signal processing method in the cause of the sampling rate is not high, in such aspects as analog video input and sampling methods put forward a new improved method; Then, adjustable high precision and high frequency difference is given the specific implementation of sampling method, and test verification; Finally, put forward the CCD signal processing related noise suppression method, and the SNR performance of CCD has carried on the detailed test. Experimental results show that the improvement of the CCD signal processing method makes the maximum sampling rate reached 80 Msps, doubled than traditional methods, the minimum sampling precision can reach 0.5 ns, and in the most measured signal-to-noise ratio under the sampling rate can still 41.2 dB, improved precision adjustable and high frequency difference sampling technique improves the CCD image signal-to-noise ratio, can satisfy the application requirement of high frequency CCD signal processing.