New stability constraints for pseudo-acoustic finite difference TTI modelling and inversion Available to Purchase

In contrast to ad-hoc solutions found in the literature, we propose a new systematic and automated approach to generate shear-wave velocity models needed for stable pseudo-acoustic wave-equation modelling and inversion over vertical or tilted transverse isotropic media. Our method ensures elastic stability everywhere in the velocity model and avoids instabilities caused by grid points where (𝜖−𝛿)<0. We derive our method from first principles and refine the shear-wave velocities to reduce interference with P-waves, curb SV wavefront triplications, and damp artifacts at interfaces between anisotropic and acoustic/isotropic parts of the model. We demonstrate our novel approach with Born modelling examples over various tilted transverse isotropic models and show its effectiveness in producing stable wavefields.