Seismic diffraction tomography technique using very fast simulated annealing method for delineating small subsurface features

Abstract

Diffraction, once considered noise rather than signal in seismic tomography, has recently been successfully used for delineating smaller objects whose size is comparable to or less than the wavelength of the incident seismic wave. But Most of the seismic diffraction tomography works are based on Born's and Rytov's approximation of weak scattering to linearize the expression for the scattered field due to an object and this is the basis of Fourier Diffraction Theorem. However, In this paper, we used the amplitude of the total scattered wave field without considering any approximation of weak scattering to obtain the synthetic scattered field data for forward modeling. These synthetic data are then inversed by Very Fast Simulated Annealing method which is a nonlinear inversion technique to obtain the unknown model parameters. This algorithm is applicable to both weak as well as strong scatterers. The simulated results give fairly good estimate for unknown model parameters of the scattering object within acceptable error limits.