计算地震初至波视出射角方法

The Calculation Method of Apparent Emergence Angle of Seismic First-arrival Wave

摘要:

在理论上证明了使用地震初至波位移、速度或加速度记录资料在时间域或频率域计算视出射角,使视出射角计算不受位移记录及时间域限制。在干扰信号频率段与有效信号频率段存在差异时分别在时间域和频率域进行了视出射角计算,结果表明在频率域中得到的视出射角基本与理论值相符,与方位角无关;而在时间域中获得的视出射角与理论值波动很大。应用实际地震波记录资料计算了不同台站的视出射角,其结果同样表明在频率域中获得的视出射角比时间域视出射角更加稳定和可信。

Abstract:

In time domain or frequency domain,using displacement,velocity or acceleration of seismic first-arrival wave,the apparent emergence angles are separately calculated.In theory it is proved that calculating apparent emergence angle is not limited by displacement records and time domain.Considering the difference between frequency ranges of interference signal and effective signal,respectively in time domain and frequency domain the apparent emergence angles are calculated,the result shows that the apparent emergence angle in frequency domain basically is equal to the theoretical value,has nothing to do with the azimuth,but the angle has big fluctuation with theoretical value in time domain.It indicates that the apparent emergence angle is less affected by interference signal in frequency domain.Appling the method and using real seismic wave records,the apparent emergence angles of seismic first-arrival wave in some stations are calculated,the results indicate that the apparent emergence angle is more stable and credible in frequency domain than in time domain.