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Travel-time Tomography For High Contrast Media based on Sparse Data. Yenting Lin. Signal and Image Processing Institute Department of Electrical Engineering University of Southern California. February 3, 2013. Computed Travel-time Tomography.
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Travel-time Tomography For High Contrast Media based on Sparse Data Yenting Lin Signal and Image Processing Institute Department of Electrical Engineering University of Southern California February 3, 2013
Computed Travel-time Tomography • Computed travel-time tomography is a powerful tool to produce tomographic image • Measure the signal response on the boundary • Slices of specific area of the object, Non-destructive detection • Widely used in geophysical and medical imaging
Problems • Not enough data - samples may be expensive • Travel-time tomography in geophysical application: Very expensive to setup sensors, drilling costs much time and money • Under-determined nonlinear inverse problem • High contrast structure • Some natural structure have high contrast property • Only need to separate the target structure and the background • Typical grid-based model and iterative reconstruction won’t work well in this case
Our work • Reconstruct high contrast structure based on sparse travel-time data • Object based model – reduce the dimensionality • The solution is not unique - estimate the probability distribution of different models by randomized sampling techniques Grid based model Object based model
Water-flood tomography • Apply our algorithm in petroleum application • Water is injected to support the pressure in the reservoir • Use well injection and production data to estimate the equivalent travel-time between well pairs • Estimate the high permeability areas in an oil field Ground truth in Simulator Probability map of high perm