基于时序相关双采样的紫外光谱CCD信号采集

Signal Acquisition for Spectrum UV CCD Based on Timing Correlated Double Sampling

目前采集CCD信号通常是使用双采样器来实现,仅适用于高频采样。为扩大采样频率范围和提高采集精度,采用了一种基于时序相关双采样的采集方法。时序相关双采样是在时序上分别选取CCD输出信号复位电平和信号电平中的2小段进行AD转换,转换后的数据上传到上位机上相减得到像素的实际灰度值。用紫外光源配合紫外滤色片进行了相应实验,结果表明,该方法能在不同频率下对紫外光谱CCD信号进行正确采集并成像。分析采集结果可知,该方法能消除信号电平和复位电平整体漂移产生的误差,抑制系统噪声。

Double samplers were usually used for signal acquisition of CCD currently, but they were only suitable for high frequency sampling. In order to expand the scope of the sampling frequency and improve collection accuracy, a method of acquisition was used, which is based on the timing correlated double sampling. Its principle is selecting two short sections in the CCD output signal in reset level and signal level on the timing for AD conversion, and uploading the digital data to the PC for subtraction to get pixel gray value. Related experiments with UV light source and UV filter were done. The results show that this method can collect the signal of UV spectrum CCD and image correctly at different frequencies. Analyses of the results show that this method can eliminate the errors caused by signal level, reset level overall drifting and suppress system noise.