generally, the measured secondary field data is inverted into resistivity using two principal models; the homogeneous half-space model and the layered half-space model. while the homogeneous half-space inversion uses single frequency data, the inversion is done individually for each of the frequencies used, the multi-layer 1d inversion is able to take the data of all frequencies available into ...

Compressive sensing (CS) is an emerging field that, under appropriate conditions, can significantly reduce the number of measurements required for a given signal. Specifically, if the m-dimensional signal u is sparse in an orthonormal basis represented by the m × m matrix Ψ, then one may infer u based on n m projection measurements. If u = Ψθ, where θ are the sparse coefficients in basis Ψ, the...

Full waveform inversion (FWI) delivers high-resolution images of the subsurface by minimizing iteratively the misfit between the recorded and calculated seismic data. It has been attacked successfully with the GaussNewton method and sparsity promoting regularization based on fixed multiscale transforms that permit significant subsampling of the seismic data when the model perturbation at each F...

Inversion of magnetic data is an important step towards interpretation of the practical data. Smooth inversion is a common technique for the inversion of data. Physical bound constraint can improve the solution to the magnetic inverse problem. However, how to introduce the bound constraint into the inversion procedure is important. Imposing bound constraint makes the magnetic data inversion a n...

In this paper, we studied effect of different parameters including density, viscosity, interfacial tension and solute transfer concentration on phase inversion hold-up. The results showed that change in phase density ratio had no effect on phase inversion hold-up. It also disclosed that the phase viscosity ratio was the most effective parameter affecting phase inversion hold-up and each phase h...

Gravity data inversion is one of the important steps in the interpretation of practical gravity data. The inversion result can be obtained by minimization of the Tikhonov objective function. The determination of an optimal regularization parameter is highly important in the gravity data inversion. In this work, an attempt was made to use the active constrain balancing (ACB) method to select the...

A group sparsity penalized CSI in the wavelet domain is proposed to alleviate ill-posedness within framework of a contrast-source inversion (CSI) method. It then applied retrieval large inhomogeneous dielectric scatterer from time-harmonic single-frequency data. As dependency exists between coefficients at different scales, referred as parent-child relationship, it enables yield quad tree struc...