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Line-source simulation for shallow-seismic data. Part 2: full-waveform inversion - a synthetic 2-D case study

Schäfer, Martin; Groos, Lisa; Forbriger, Thomas; Bohlen, Thomas

Abstract:
Full-waveform inversion (FWI) of shallow-seismic surface waves is able to reconstruct lateral variations of subsurface elastic properties. Line-source simulation for point-source data is required when applying algorithms of 2-D adjoint FWI to recorded shallow-seismic field data. The equivalent line-source response for point-source data can be obtained by convolving the waveforms with sqrt(1/t) (t: traveltime), which produces a phase shift of π/4. Subsequently an amplitude correction must be applied. In this work we recommend to scale the seismograms with sqrt(2*r*v_ph) at small receiver offsets r, where v_ph is the phase velocity, and gradually shift to applying a sqrt(1/t) time-domain taper and scaling the waveforms with r*sqrt(2) for larger receiver offsets r. We call this the hybrid transformation which is adapted for direct body and Rayleigh waves and demonstrate its outstanding performance on a 2-D heterogeneous structure. The fit of the phases as well as the amplitudes for all shot locations and components (vertical and radial) is excellent with respect to the reference line-source data. An approach for 1-D media base ... mehr


Zugehörige Institution(en) am KIT Geophysikalisches Institut (GPI)
Publikationstyp Zeitschriftenaufsatz
Jahr 2014
Sprache Englisch
Identifikator ISSN: 0956-540X
KITopen ID: 1000042250
Erschienen in Geophysical Journal International
Band 198
Heft 3
Seiten 1405-1418
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