| Abstract: | The stable-beam method for forward modelling of seismic data is introduced. The method is applicable to geometries which may be approximated by a series of single-valued (in depth) interfaces separating constant-velocity layers. For models of this restricted type, the results are of similar accuracy to those from waveequation-based methods whilst the run times are similar to, or better than, those for simple ray-tracing approaches. The basis of the method is to approximate interfaces by a series of straight-line segments. This allows very rapid and stable ray tracing through the model. Pseudodiffractions are then added from all of the interface discontinuities formed between adjacent segments. These pseudodiffractions have the effect of correcting for the phase, amplitude and wavefront continuity errors introduced by the interface approximation. Comparison of the stable-beam results to analytical, Kirchhoff, finite-difference and physical model results confirm the accuracy ofthe technique. |
