多次采样平均在长波红外高光谱成像系统中的应用

长波红外高光谱成像系统由于光谱细分导致探测器所接收的目标信号的能量较一般成像系统弱,因此系统噪声对成像效果影响较大。针对这一现象,本文在分析系统噪声成分的基础上,提出采用ADC多次采样平均的方法来降低其噪声,并从理论上推导了该方法的有效性。然后搭建了实验系统,分析计算不同积分时间下,利用多次采样平均技术得到的信号和噪声大小,并计算系统的信噪比和NETD。结果表明,多次(m次)采样平均对系统的信号值几乎无影响,但可以将系统噪声降低至原来的m^-1/2倍。因此,该方法可将系统的信噪比提高至原来的m^1/2倍,并能有效降低系统的NETD,提高系统灵敏度。该方法为改善长波红外高光谱成像系统成像效果提供了一种方案。

Application of Multiple Sampling Technology in LWIR Hyperspectral Imaging System

In LWIR hyperspectral imaging systems,the target signal is much lower than in other infrared imaging systems due to spectral subdivision.Therefore,system noise has great influence on the image.In this study,the method of multiple sampling technology used by ADC was performed to decrease the system noise.First,the noise components were analyzed and the effectiveness of the multiple sampling technology was theoretically deduced.Then,an experimental system was built and the signal,noise,signal-to-noise ratio,and NETD of the system at different integration and sampling times were calculated.Results show that the multiple sampling technology has almost no influence on the value of signal and can decrease system noise to m 1/2 times the initial noise.Therefore,this method increases the signal-to-noise ratio of the system to m 1/2 times the initial ratio and significantly decreases NETD to improve system sensitivity.This method provides a solution for improving the images obtained using LWIR hyperspectral imaging systems.