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We present a general method for estimating the location of small, well-separated scatterers in a randomly inhomogeneous environment using an active sensor array. The main features of this method are (i) an arrival time analysis of the echo received from the scatterers, (ii) a singular value decomposition of the array response matrix in the frequency domain,(More)
Reconstruction of acoustic, seismic, or electromagnetic wave speed distribution from rst arrival traveltime data is the goal of traveltime tomography. The reconstruction problem is nonlinear, because the ray paths that should be used for tomographic backprojection techniques can depend strongly on the unknown wave speeds. In our analysis, Fermat's principle(More)
Introduction The purpose of this project is to develop a computer code for joint inversion of seismic and electrical data, to improve underground imaging for site characterization and remediation monitoring. The computer code developed in this project will invert geophysical data to obtain direct estimates of porosity and saturation underground, rather than(More)
Phenomenological equations (with coeecients to be determined by speciied experiments) for the poroelastic behavior of a dual porosity medium are formulated and the coeecients in these linear equations are identiied. The generalization from the single porosity case increases the number of independent coeecients for volume deformation from three to six for an(More)