天空亮度分布在大气光学领域有着重要的应用。随着天空亮度测量仪器的迅速发展, 对测量的精度和工作稳定性的要求也越来越高。为了提高测量仪器的动态测量范围, 需要实现对探测器输出的弱信号的高精度测量。讨论了用高精度运算放大器对弱信号进行放大滤波处理, 并采用一种低噪声高精度Δ-Σ型模数转换器(ADC)来解决探测器中弱信号高精度测量的设计难题, 为天空背景亮度测量仪器的研制, 特别是为在设计中常面临的弱信号的高精度检测提供了一种解决问题的有效途径。

Distribution of sky brightness is significant in atmosphere optics. With the rapid development of sky brightness measurement instrument, the demands of the instrument’s precision and long-term stability reaches to an entirely new level. In order to measure the sky brightness on the condition of weak illumination, the problem of weak signal measurement should be first solved. A solution based on High Precision Operational Amplifier and low noise high precision Δ-Σ ADC is given, it is proved that the solution is an effective means to solve the weak signal measurement in the field of optical measurement instruments’ design.