论文部分内容阅读
电荷耦合器件(CCD)是遥感成像系统的核心部件,为了在低照度、低量化位数的情况下获得高信噪比与大动态范围的遥感图像,首先根据CCD的结构与噪声物理性质给出了模拟增益、量化位数与CCD信噪比的关系,接着搭建了CCD的积分球标定系统,依据实验数据建立了散粒噪声、光子响应非均匀性噪声以及基底噪声的数学模型,然后着重分析了低照度情况下模拟增益与信噪比之间的关系,最后搭建了实际成像系统,获取了低照度情况下不同模拟增益系数的遥感图像.结果表明理论分析、实验室积分球标定数据与实际成像图像符合良好,即模拟增益提高1至2倍,可显著提高CCD信噪比,同时获得较大的动态范围.
Charge-coupled device (CCD) is the core component of remote sensing imaging system. In order to obtain remote sensing images with high signal-to-noise ratio (SNR) and large dynamic range under low illumination and low quantization bit number, CCD structure and noise physical properties The relationship between analog gain, quantization bits and CCD signal-to-noise ratio is established. Then a CCD integrating sphere calibration system is set up. Based on the experimental data, mathematical models of shot noise, photon response inhomogeneity noise and substrate noise are established. The relationship between analog gain and signal-to-noise ratio under low illumination, and finally set up the actual imaging system, obtained the remote sensing images of different analog gain coefficients under low illumination.The results show that the theoretical analysis, calibration data of laboratory integrating sphere and actual The image is in good agreement, that is, an increase of 1 to 2 times the analog gain can significantly improve the CCD signal to noise ratio, while obtaining a larger dynamic range.