Seismic amplitude inversion for interface geometry of multi-layered structures

Seismic amplitude data are used to invert for the geometry of reflection interfaces of multi-layered structures, in which the reflection interface is parameterised by a set of Fourier series with different wavenumbers. Two main difficulties arise in amplitude inversion: a high wavenumber oscillation artificially generated by inversion on shallow interfaces, and a failure to recover the long wavelength components of deep, curved interfaces. To overcome these difficulties, the capabilities of two inversion algorithms, a damped subspace method and a multi-scale scheme are investigated. Based on those two schemes, we develop a multi-stage damped subspace method to abate the instability of high wavenumber components and, simultaneously, to enhance the resolution of the low wavenumber components of the subsurface reflectors from seismic amplitude inversion.