From Approximate to Accurate Velocity Rays

P107 From approximate to accurate velocity rays Summary 1 EINAR IVERSEN NORSAR P.O. Box 51 N-2027 Kjeller Norway A new process for generation of accurate velocity rays in 3D models has been developed. The velocity rays describe the changes in isochron points and slowness vectors when a model parameter is allowed to vary. The process is organized with ODE solvers on two levels where the upper level is model independent. The lower level includes conventional one-way kinematic and dynamic tracing of source and receiver rays as well as estimation of ray perturbation quantities. Accurate velocity rays are expected to be