Non-linear optimization for seismic traveltime tomography

Seismic Traveltime Tomography 1

Temporal Integration Of Seismic Traveltime Tomography

Time-lapse geophysical measurements and seismic imaging methods in particular are powerful techniques for monitoring changes in reservoir properties. Traditional time-lapse processing methods treat each dataset as an independent unit and estimate changes in reservoir state through differencing these separate inversions. We present a general least-squares approach to jointly inverting time-varyi...

Applying Compactness Constraints To Seismic Traveltime Tomography

Tomographic imaging problems are typically ill-posed and often require the use of regularization techniques to guarantee a stable solution. Minimization of a weighted norm of model length is one commonly used secondary constraint. Tikhonov methods exploit low-order differential operators to select for solutions that are small, flat, or smooth in one or more dimensions. This class of regularizin...

Dynamic ray tracing and traveltime corrections for global seismic tomography

We present a dynamic ray tracing program for a spherically symmetric Earth that may be used to compute Fréchet kernels for traveltime and amplitude anomalies at finite frequency. The program works for arbitrarily defined phases and background models. The numerical precisions of kinematic and dynamic ray tracing are optimized to produce traveltime errors under 0.1 s, which is well below the data...

Constraints on Minimum Velocity Variance for Seismic Traveltime Tomography

SUMMARY Traveltime data together with known spacing between sources and receivers for seismic transmission tomography can be used to determine rigorous constraints on the minimum and maximum wave speeds in the propagating medium. These constraints lead to a new minimum variance criterion on inversion algorithms. These results do not improve the velocity reconstructions directly , but provide ri...