From tomography to full-waveform inversion with a single objective function
Type
ArticleAuthors
Alkhalifah, Tariq Ali
Choi, Yun Seok
KAUST Department
Earth Science and Engineering ProgramPhysical Science and Engineering (PSE) Division
Seismic Wave Analysis Group
Date
2014-02-17Online Publication Date
2014-02-17Print Publication Date
2014-03Permanent link to this record
http://hdl.handle.net/10754/576011
Metadata
Show full item recordAbstract
In full-waveform inversion (FWI), a gradient-based update of the velocity model requires an initial velocity that produces synthetic data that are within a half-cycle, everywhere, from the field data. Such initial velocity models are usually extracted from migration velocity analysis or traveltime tomography, among other means, and are not guaranteed to adhere to the FWI requirements for an initial velocity model. As such, we evaluated an objective function based on the misfit in the instantaneous traveltime between the observed and modeled data. This phase-based attribute of the wavefield, along with its phase unwrapping characteristics, provided a frequency-dependent traveltime function that was easy to use and quantify, especially compared to conventional phase representation. With a strong Laplace damping of the modeled, potentially low-frequency, data along the time axis, this attribute admitted a first-arrival traveltime that could be compared with picked ones from the observed data, such as in wave equation tomography (WET). As we relax the damping on the synthetic and observed data, the objective function measures the misfit in the phase, however unwrapped. It, thus, provided a single objective function for a natural transition from WET to FWI. A Marmousi example demonstrated the effectiveness of the approach.Citation
From tomography to full-waveform inversion with a single objective function 2014, 79 (2):R55 GEOPHYSICSPublisher
Society of Exploration GeophysicistsJournal
GEOPHYSICSAdditional Links
http://library.seg.org/doi/abs/10.1190/geo2013-0291.1ae974a485f413a2113503eed53cd6c53
10.1190/geo2013-0291.1