
%0 Journal Article
%A Nadri, D. 
%A Bona, A. 
%A Urosevic, M. 
%T Nonlinear estimation of Thomsen anisotropy parameters in TI media
%J ASEG Extended Abstracts
%D 2009/01/01
%V 2009
%N 1
%P 1-9
%K 
%R https://doi.org/10.1071/ASEG2009AB030
%U https://www.publish.csiro.au/paper/ASEG2009AB030 
%X Transverse isotropy with the horizontal axis of symmetry (HTI) is the simplest anisotropic model to characterize a geological formation with vertical fractures. We formulate an azimuthally dependent parametric equation for P-wave traveltimes in a layered HTI medium. Also, assuming a known vertical velocity model, we estimate simultaneously the fracture orientation and Thomsen?s anisotropy parameters in a stack of horizontal layers using a modified preconditioning conjugate gradient algorithm. In a numerical example, we show that in the context of weak anisotropy, Thomsen?s anisotropy parameters (delta and epsilon) and fracture orientation can be efficiently estimated using the P-wave traveltimes without a prior information. 
