Joint application of τ-p and phase-shift stacking method to extract ground wave dispersion curve
Shao Guang-zhou1,2, Li Qing-chun1,2
1. Ministry of Education Key Lab of Western Mineral Resources and Geological Engineering,Chang'an University,Xi'an City,Shaanxi Province,710054,China;
2. Applied Geophysics Institute,Chang'an University,Xi'an City,Shaanxi Province,710054,China
Abstract：For the common multiple mode dispersion curve extraction methods,f-k method requires equal sampling rate in both space domain and time domain,if there are bad traces in the datasets,the f-k spectrum could be greatly affected,so the extraction accuracy of the dispersion curve could be affected as well.The τ-p transform method has a bad extraction effect for low frequency band of the fundamental mode,but it has very good resolving ability for high order mode.Phase shift method is just the opposite with better extraction effect for fundamental mode and lower resolution for high order mode.An improved dispersion curve extraction method was proposed in this paper,the basic idea of the method is just joint application of the τ-p transform method and phase shift method,as a result the advantage of each method could be combined,the extraction effect for low frequency band of the fundamental mode was enhanced while the resolution for high order mode got raised.The theoretical model synthetic record and field data processing results show that the new joint method proposed in this paper combined the advantage of both τ-p transform method and phase shift method,so that the ideal extraction effect was achieved.
