为了提高同步辐射红外光源的光子通量和亮度以及改善光学元件的热稳定性,同步辐射光源现多采用恒流注束(Top-Up)模式,以保持储存环内部束流的稳定.在增强器向储存环注束时,储存环电流的瞬时起伏及电子束团位置的变动等会使同步辐射红外线站所用红外傅立叶变换(FTIR)光谱仪所采的干涉图上出现较大的波动,形成噪声；本文根据该噪声的特点,以及全域中值滤波算法处理该类型的噪声的不足,提出使用区域中值滤波算法对红外谱学线站使用的FTIR光谱仪所采的干涉图进行预处理,以消除由Top-Up模式引入的噪声的影响；并根据该型噪声的特点和区域中值滤波算法的处理过程,设计了一套去除由Top-Up模式引入的同步辐射红外谱学噪声的流程,使该区域中值滤波算法的处理过程无需人工干预；使用该区域中值滤波算法对具有该型噪声的干涉图进行了降噪处理,计算结果表明：使用该滤波算法可消除由Top-Up模式引入噪声的影响,提升Top-Up模式下所采光谱的信噪比.

In order to enhance the photon flux and brightness of a synchrotron source, and improve the thermal stability of optical elements, synchrotron radiation source often operates in the qusi-constant current injection (Top-Up) mode. The Top-Up mode can maintain a stable beam current in the storage ring of Synchrotron Source. When the electron is injected into the storage ring from the booster, a noise induced by the instantaneous fluctuation of the beam current in the storage ring will cause a large fluctuation on the interferogram, which can be observed by the FTIR spectrometer used in IR experimental endstation. The median filtering algorithm is not sufficient to filter the noise according to the noise characteristics. Therefore, a zone median filter method is proposed to eliminate the noise introduced by the Top-Up mode. A set of the processes of zone median filtering algorithm is designed, which can eliminate the Top-Up mode induced noise on the interferogram automatically. Simulation results show that: the filtering algorithm can be applied to eliminate the noise on the interferogram introduced by the Top-Up mode effectively,so the method can be used to enhance the spectral SNR of the spectrum in the Top-Up mode.