Application of the redundant-lifting scheme for ground-roll attenuation in near-surface characterization using full-waveform inversion on P-wave seismic data |
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| Authors: | Md Iftekhar Alam Khemraj Shukla |
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| Institution: | 1. Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, 37996;2. School of Geology, Oklahoma State University, Stillwater, OK, 74078 |
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| Abstract: | Seismic modelling of the shallow subsurface (within the first few metres) is often challenging when the data are dominated by ground-roll and devoid of reflection. We showed that, even when transmission is the only available phase for analysis, fine-scale and interpretable P-wave velocity (VP) and attenuation (QP?1) models can still be prepared using full-waveform inversion, with data being preconditioned for ground-roll. To prove this idea, we suppressed the ground-roll in two different ways before full-waveform inversion modelling: first, through a bottom mute; second, through a novel wavelet transform-based method known as the redundant-lifting scheme. The applicability of full-waveform inversion is tested through imaging two buried targets. These include a pair of utility water pipes with known diameters of 0.8 m and burial depths of 1.5 m, respectively. The second target is the poorly documented backfill, which was the former location of the pipe(s). The data for full-waveform inversion are acquired along a 2D profile using a static array of 24, 40 Hz vertical component geophones and a buried point source. The results show that (a) the redundant-lifting scheme better suppresses the ground roll, which in turn provides better images of the targets in full-waveform inversion; and (b) the VP and QP?1 models from full-waveform inversion of redundant-lifting scheme data could detect the two targets adequately. |
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| Keywords: | Inversion Near-surface Seismics |
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