高分辨力遥感相机CCD采样位置自适应补偿技术

Adaptive compensation technique for CCD signal sampling positions in high-resolution remote sensing cameras

由于受温度变化的影响,高分辨力遥感相机焦平面CCD采样信号的相位会发生变化,采样位置的温度漂移会严重影响图像的信噪比、动态范围等,甚至会造成图像无法正常显示。为了解决采样位置随温度漂移的问题,对高分辨力遥感相机CCD采样位置进行了自适应补偿设计,首先对CCD采样信号的初始位置进行精密调节,然后设计了自适应补偿电路,通过对功耗的控制使各驱动芯片温度基本一致,CCD信号与采样信号在温度变化上具有跟踪性,在动态上保证CCD信号采样位置的准确性,从而保证图像信噪比的稳定性。实验表明,利用该方法,相关双采样信号的初始位置调节精度小于0.039 ns;在卫星在轨温度范围内,相关双采样信号延时最大值为0.46 ns,保证了相机的高质量成像,满足航天应用需要。

Under the influence of temperature changes,the phase of the CCD sampling signal of a high-resolution remote sensing camera canvary.This canadversely affect the signal-to-noise ratio and dynamic range of the imageand may even cause the image to be displayedabnormally.To solve this problem of temperature-relatedsampling position drift,an adaptive compensation design was developed for the CCD sampling position of a high-resolution remote sensing camera.First,the initial position of the CCD sampling signal was precisely adjusted,and an adaptive compensation circuit was then designed tocontrol the power consumption,which rendered the temperature of each driver chipto be essentially the same.The advantage of this method is that the CCD and sampling signals can be effectively monitored during temperature changes,thus,ensuring the accuracy of the sampling position of the CCD signal and stability of the signal-to-noise ratio of the image.The experiments indicate that with this method,the accuracy of the initial position adjustment of the correlated double-sampling signal improves to less than 0.039 ns.Additionally,the maximum delay of the correlated double-sampling signal in the satellite in-orbit temperature range is 0.46 ns,which ensures high-quality imaging and meets the requirements of space applications.