中值滤波器对信号相位和形状影响的研究

The impacts of median filter to the phases and shapes of signals

吉林大学朝阳校区地球物理系, 吉林长春130026

Dept. of Geophysics, Jilin University, Chaoyang Campus, Changchun 130026,China

中值滤波器具有许多优点,已经在VSP等地震资料处理中得到较为广泛的应用。由于中值滤波器是一种非线性滤波器,对尖脉冲的响应是零,在傅氏域没有“真正”的振幅谱和相位谱,所以了解其特性比了解线性滤波器特性要困难得多。然而许多简单的数值方法可合理、直观地了解这种滤波器在地震资料中的作用。

Although median filter has been widely used in seismic data processing, especially in processing of VSP data due to its many merits, it is difficult to understand the behaviors of the median filter, because it is one kind of nonlinear filter with zero response to spike pulse, and has no "actual" amplitude and phase spectrum. However, the effects of the filter can still be analyzed via many straightforward numerical means. Among them analysis of its responses to different signals is an effective and practical way to study the behaviors of the filter. Some characteristics of the median filter are presented in the paper.