Generation of a pseudo-2D shear-wave velocity section by inversion of a series of 1D dispersion curves

摘要: Abstract Multichannel Analysis of Surface Waves utilizes a multichannel recording system to estimate near-surface shear (S)-wave velocities from high-frequency Rayleigh waves. A pseudo-2D S-wave velocity ( v S ) section is constructed by aligning 1D models at the midpoint each receiver spread and using spatial interpolation scheme. The horizontal resolution therefore most influenced length source interval. sets theoretical lower limit any structure with its lateral dimension smaller than this will not be properly resolved in final section. interval improve because smearing has already been introduced spread. In paper, we first analyze pair synthetic traces. Resolution analysis shows that (1) traces spacing achieves higher inverted but results larger relative error; (2) error phase high frequency low frequency; (3) affected signal-to-noise ratio data. These provide us guideline balance trade-off between (horizontal resolution) accuracy velocity. We then present scheme generate records inverting surface-wave dispersion curves calculated through cross-correlation combined phase-shift scanning method. This method chooses only consecutive within shot gather calculate curve. finally invert real-world Inversion both data demonstrate – damped least-square singular-value decomposition technique can feasibly achieve reliable relatively resolution.