中文摘要：

傅里叶红外光谱仪使用的红外探测器频率响应范围通常为几十Hz到数MHz，这使得探测器直接接收的干涉信号中很容易混入环境噪声，引起真实干涉信号的畸变。过采样型傅里叶红外光谱仪等同于将传统光谱仪的等光程间隔采样过程“搬移”到计算机内，因此，理论上允许使用数字滤波器代替模拟滤波器对红外干涉信号降噪。在分析过采样型傅里叶红外光谱仪红外干涉信号有效频率范围的基础上，详述了适用于过采样型傅里叶红外光谱仪的巴特沃斯数字带通滤波器的设计方法，并应用设计的滤波器对过采样的红外干涉信号进行了降噪研究。结果表明：数字滤波的方法能有效去除红外干涉信号中的高、低频噪声，保留真实的光谱信号，在使用上也比模拟滤波更加灵活、便捷。

英文摘要：

The frequency response range of infrared detector in Fourier transform infrared spectrometer extends from dozens of Hz to some MHz generally. Because of wide frequency response, the measured signal will be easily blurred by lower and higher frequency noise from ambient. Noise can deform the real infrared interference signal. Compared with traditional Fourier transform infrared spectrometer, the oversampling one seems like to put the equal-spacing sampling procedure into computer. Therefore, it will be possible to lay a digital filter after the oversampling infrared interference signal. Based on evaluation of effective frequency response range of infrared interference signal, the design method of a Buttworth bandpass digital filter was illustrated. With this designed filter, the noise of oversampling infrared interference signal could be filtered. The experimental results show that the designed filter can effectively filter higher and lower noise to keep real spectral signal. Additionally, the digital filter is easier and more flexible to design than analog one.