光学 精密工程, 2011, 19 (11): 2800, 网络出版: 2011-12-05
高分辨力遥感相机视频处理的温度适应性设计
Design of temperature adaptability for video processing in high-resolution remote sensing cameras
高分辨力遥感相机 成像系统 温度适应性 相关双采样 high resolution remote sensing camera imaging system temperature adaptability Correlated Double Sampling (CDS)
摘要
对遥感相机成像电子学系统进行了温度适应性设计,以使其在温度大范围变化时或电路存在局部温差时均能实现高质量成像。分析了成像链路中的温度延时因素,提出了温度适应性设计方案和相关双采样(CDS)位置的初始精密对准方法,并进行了实验验证。该方法将CCD驱动器的输出经分压整形处理后作为双采样信号的时序基准,从而使双采样信号具备自适应跟踪能力;利用RC电路低通滤波特性对双采样初始位置进行精密对准,最后,在-35~75 ℃对改进后的遥感相机成像电子学系统进行了高低温实验。结果表明:双采样初始位置的延时调节精度达到了0.15 ns;在实验温度范围内,双采样偏离理想位置的延时最大值仅为0.72 ns,相机成像质量达到指标要求,满足空间应用需要。
Abstract
To obtain high quality images for remote sensing cameras in a wider temperature change or in the temperature diversity caused by different circuit parts, an adaptive method for imaging electronics was proposed. The time-delay factors of temperature in the imaging system was analyzed, and design methods for temperature adaptability and the initial alignment of Corrlated Double Sampling(CDS) positions were given. Several experiments were performed to validate the feasibility of this method. By proposed method, the output of CCD driver was divided and was taken as a benchmark for the CDS signals, so that CDS signals can be used to track the driving signal adaptively. Then, initial positions of CDS were precisely aligned by using the lowpass filtering of a RC net. Finally, a temperature experiment by proposed compensating method was carried out for the imaging system of remote camera in -35~75 ℃. Results indicate that the position precision of CDS signals after adjusting is up to 0.2 ns. In the experimental temperature range, the maximal deviation of the CDS signals is only 072 ns as comparing with that of ideal one, which satisfies the indicators of image quality and the requirements of space application.
曲利新. 高分辨力遥感相机视频处理的温度适应性设计[J]. 光学 精密工程, 2011, 19(11): 2800. QU Li-xin. Design of temperature adaptability for video processing in high-resolution remote sensing cameras[J]. Optics and Precision Engineering, 2011, 19(11): 2800.