【摘要】 地震信号属于非平稳信号,利用短时傅立叶变换对地震信号进行时频分析时会受窗口大小的影响,利用Wigner-Ville分布的方法时会产生交叉项。基于这些原因,提出了把二者结合起来的方法计算时频分布,并且利用时频剖面得到信号的瞬时频率。从理论数据出发,分别计算利用短时傅立叶变换、Wigner-Ville及二者结合得到的时频剖面。通过比较得出:2类方法联合后获取的瞬时频率与原始的瞬时频率最接近,说明二者结合的方法对获取瞬时频率更有效。更多还原

【Abstract】 Seismic signal is non-stable signal.The time-frequency analysis result of short-time Fourier transform is affected by the window size.The time-frequency analysis result of Wigner-Ville is affected by the cross part.Based on the advantage and disadvantage of linear time-frequency method and non-linear time-frequency method,the author proposes to obtain the time-frequency profile using the method of combination for linear time-frequency and non-linear time-frequency method.Then the instantaneous frequency can be obtained in the time-frequency profile.The author computes the time-frequency distribution using the short-time Fourier transform method,Wigner-Ville method and the combination of short-time Fourier transform and Wigner-Ville method for theoretical data.A comparison indicates that the result of combination of short-time Fourier transform and Wigner-Ville method is very close to the theoretical instantaneous frequency.The method is effective for computing instantaneous frequency.更多还原