基于S变换和瞬时旅行时属性的自动初至拾取方法研究

地震波走时拾取是地震资料前期处理过程中的一个重要步骤,同时也是后期层析成像方法中计算速度的重要依据。本文提出了一种新的自动初至拾取的方法,利用地震信号的瞬时旅行时属性进行地震波自动初至拾取,瞬时旅行时属性的计算包括两个独立但相关联的部分,首先通过S变换将地震信号转换到时频域,然后利用映射算子将时频域表征映像回时间域得到瞬时旅行时,从而实现自动拾取初至。理论模型和实际地震资料处理的结果表明,该方法可以有效地拾取地震波初至时间。

Automatic firstbreak picking method based on S transform and instantanous traveltime attributes

Firstbreak picking is an important step in the seismic data processing，and it is the important basis of speed calculation in tomographic imaging． We present an automatic firstbreak picking method based on instanta- neous traveltime． The calculation of the instantaneous traveltime consists of two separate but interrelated stages． First，a trace is mapped onto the time- frequency domain． Then the time- frequency representation is mapped back onto the time domain by an appropriate operation． In this paper we chose S transform to map the seismic trace onto time- frequency domain，so as to realize automatic firstbreak picking． Synthetic model and field seismic data show that the proposed method can effectively do the automatic firstbreak picking．