中文摘要：

地空瞬变电磁信号中含有大量干扰噪声,尤其是晚期信号干扰影响较大,若不对其进行滤波处理,将会影响瞬变信号的分析及反演成像的质量。传统的傅里叶变换不能分辨正常信号中夹带的瞬态反常现象,也不能展示其成分,无法满足非平稳信号的分析要求;而瞬变电磁信号是一种动态、瞬态的信号。因此采用短时傅里叶变换（STFT）进行数据分析,并开发了一套基于LabVIEW的预处理软件,用于现场快速分析地空瞬变电磁信号。实验结果表明,预处理软件对地空瞬变电磁的分析和滤波处理是可行有效的,便于及时评价滤波效果,为进一步确定信号滤波方法提供了依据。

英文摘要：

There are a lot of interference noises in the ground-to-air transient electromagnetic signal,especially the late signal is greatly influenced by the interference. If the filtering processing isn＇t adopted for the interference,it may influence on the analysis of transient signal and the quality of inversion imaging. The traditional Fourier transform can＇t distinguish the transient abnormal phenomenon in normal signal and show its composition,so it can＇t satisfy the analysis requirement of the non-stationary signal. Since the transient electromagnetic signal is a dynamic and transient one,the short time Fourier transform（STFT）is adopted to analyze the data. A set preprocessing software based on Lab VIEW was developed to rapidly analyze the ground-to-air transient electromagnetic signal on site. The experimental results show that the preprocessing software is feasible and effective for the analysis of ground-to-air transient electromagnetism and filtering processing,and is convenient for evaluating the filtering effect in time. It provides the basis for further determining the signal filtering method.