面阵CCD及线阵CCD不能胜任海洋目标观测的要求,选用具有高信噪比高灵敏度的时间延迟积分CCD(Time delay integration CCD, TDI-CCD)作为 探测器并实现其驱动电路。在图像采集过程中,TDI-CCD探测器使用两个读取端口输出。 该探测器驱动电路产 生TDI-CCD和A/D的驱动时序。CCD的模拟输出信号被A/D采样,转换成可被计算机识别 的数字信号。采用FPGA作为主控芯片,产生驱动时序,接收被A/D转换过的数字信号, 并发送图像至计算机。利用相关双采样(Correlated double sampling, CDS)技术滤除TDI-CCD模 拟输出信号的相关噪声,提高信号的信噪比。现场可编程门阵列(Field programmable gate array, FPGA)代码在ISE14.7下进行仿真,实验表明,研制的TDI-CCD驱动电路能够产生CCD要求的驱动时序。

Because array CCD and linear CCD don’t meet the requirement of observing the ocean goal, the time delay integration CCD (TDI-CCD) which has high sensitivity and high signal to noise ratio is selected and driving circuit is designed. Two ports of outputs the signal during image capture. The driver circuit generates the time sequence of the CCD and the A/D. The output analog signal of the CCD is sampled by A/D and converted to the digital signal which can be recognized by computer. FPGA is used to driving CCD and A/D, receiving the digital signal after A/D converts, and sending the imaging data to computer. The correlated double sampling (CDS) can decrease some related noise which analog output signal of the TDI-CCD has, and increase the signal to noise ratio. The code of field programmable gate array (FPGA) is simulated on the ISE14.7. The experiment results prove that the driving circuit can generate right sequence that CCD needs.