We present a method for inverting surface magnetic data to recover 3-D susceptibility models. To allow the maximum flexibility model represent geologically realistic structures, we discretize region into set of rectangular cells, each having constant susceptibility. The number cells is generally far greater than available, and thus solve an underdetermined problem. Solutions are obtained by minimizing global objective function composed misfit. algorithm can incorporate priori information...

We present two methods for inverting surface gravity data to recover a 3-D distribution of density contrast. In the first method, we transform into pseudomagnetic via Poisson’s relation and carry out inversion using magnetic algorithm. second, invert directly minimum structure model. both approaches, earth is modeled by large number rectangular cells constant density, final obtained minimizing model objective function subject fitting observed data. The has flexibility incorporate prior...

In this paper, the term “depth of investigation” refers generically to depth below which surface data are insensitive value physical property earth. Estimates for dc resistivity and induced polarization (IP) surveys essential when interpreting models obtained from any inversion because structure beneath that should not be interpreted geologically. We advocate carrying out a limited exploration model space generate few have minimum differ substantially final used interpretation. Visual...

We develop three methods to invert induced polarization (IP) data. The foundation for our algorithms is an assumption that the ultimate effect of chargeability alter effective conductivity when current applied. This assumption, which was first put forth by Siegel and has been routinely adopted in literature, permits IP responses be numerically modeled carrying out two forward modelings using a DC resistivity algorithm. intimate connection between data means inversion two‐step process. First,...

In this paper wavelet transforms and a logarithmic barrier method are applied to the inversion of large-scale magnetic data recover 3-D distribution susceptibility. The fast transform is used, along with thresholding small coefficients, form sparse representation sensitivity matrix. reduced size resultant matrix allows solution large problems that otherwise intractable. compressed used carry out forward modelling by performing matrix-vector multiplications in domain. reduction CPU time...

Three-dimensional (3D) inversion of magnetic data to recover a distribution susceptibility has been successfully used for mineral exploration during the last decade. However, unknown direction magnetization limited use this technique when significant remanence is present. We have developed comprehensive methodology solving problem by examining two classes approaches and formulated suite methods practical utility. The first class focuses on estimating total then incorporating resultant into...

Geophysical inversion methods are used as part of an interpretation process that seeks to differentiate geologic units. To improve the reliability differentiation based on recovered images from geophysical inversions, we have developed a multidomain clustering algorithm can incorporate statistical petrophysical data into deterministic framework through use fuzzy c-means technique. Petrophysical treated in parameter domain same way spatial domain, and these two different types simultaneously...

Joint inversion of multiple geophysical data has become an active area research due to its potential greatly enhance the fidelity inverted models. Many open questions and challenges still remain. One them is how effectively incorporate into joint multimodal petrophysical information that describes statistical behavior physical property values in parameter domain (i.e., a crossplot). We have regarded as different clusters developed approach handles through guided fuzzy c-means (FCM)...

We present a case study of applying 3D inversion gravity gradiometry data to iron ore exploration in Minas Gerais, Brazil. The bodies have distinctly high-density contrast and produce well-defined anomalies airborne data. carried out apply [Formula: see text] subarea from larger survey demonstrate the utility such associated algorithm characterizing deposit. examine multiple density models obtained by first inverting text]; then text], jointly; finally all five independent components...

Abstract Minimum-structure inversions using L 2-norm measures have been widely applied to geophysical exploration problems. However, the smeared-out models resulting from are not always consistent with real or expected geological structures, especially in regions where distinct interfaces between different rock units exist. To obtain sharp boundaries and blocky features, non-L 2 used successfully imaging In reality, however, both smooth features can be present subsurface physical properties...

Joint inversion that simultaneously inverts multiple geophysical data sets to recover a common Earth model is increasingly being applied exploration problems. Petrophysical can serve as an effective constraint link different physical property models in such inversions. There are two challenges, among others, associated with the petrophysical approach joint inversion. One related multimodality of because there often exist more than one relationship between properties region study. The other...

Defect engineering is a proven method to tune the properties of perovskite oxides. In demanding high-power piezoelectric ceramic applications, acceptor doping most effective harden ceramics, but it inevitably degrades ceramics' electromechanical properties. Herein, poling based on doping, namely, high-temperature poling, implemented by applying an electric field above Curie temperature for achieve balance coefficient d33 and mechanical quality factor Qm. After property 0.6 mol % Mn-doped...

The inversion of magnetic data is inherently nonunique with respect to the distance between source and observation locations. This manifests itself as an ambiguity in depth when surface are inverted boreholes if borehole inverted. Joint can help reduce this nonuniqueness. To achieve this, we develop algorithm for inverting sets that have arbitrary locations above surface. depends upon weighting functions counteract geometric decay kernels from observer. We apply these three‐component...

The characterization and interpretation of magnetic anomalies rely upon knowledge the total magnetization direction. Magnetization is usually assumed to consist solely, or primarily, induced magnetization. presence strong remanent can alter direction significantly consequently adversely affect interpretation, leading erroneous sizes shapes causative bodies. Therefore, it imperative have some understanding We propose a method based correlation between two quantities in data interpretation:...

The presence of remanent magnetization has hindered the application generalized 3D magnetic inversion in exploration geophysics because unknown and variable directions. Although many authors have developed different approaches to deal with this difficulty, it remains a challenge. We new approach for inverting total-field anomaly recover distribution by using fuzzy c-means clustering technique. approximates variation directions small number possible orientations thereby achieves stability...

We present an algorithm for inverting induced polarization (IP) data acquired in a 3-D environment. The is based upon the linearized equation IP response, and inverse problem solved by minimizing objective function of chargeability model subject to bound constraints. minimization carried out using interior‐point method which bounds are incorporated logarithmic barrier solution linear equations accelerated wavelet transforms. Inversion requires knowledge background conductivity. study effect...

We present a method for separating regional and residual magnetic fields using 3-D inversion algorithm. The separation is achieved by inverting the observed data from large area to construct susceptibility distribution. field produced model then used as field, are obtained simple subtraction. advantages of this that it introduces little distortion shape extracted anomaly not affected significantly factors such topography overlap power spectra fields. proposed tested synthetic example having...

In an E-SCAN DC resistivity experiment a large amount of common source pole-pole potential data from many sources over pre-designed survey grid are collected. The number potentials and the spatial configuration in which they collected invite development new imaging inversion methods. We present three one-pass algorithms. They based upon linearized equation for under Born approximation assumption that conductivity model consists perturbations to uniform background conductivity. Two algorithms...

PreviousNext No AccessSEG Technical Program Expanded Abstracts 20013‐D inversion of gravity gradiometer dataAuthors: Yaoguo LiYaoguo LiGravity and Magnetics Research Consortium, Department Geophysics, Colorado School Mines, Golden, COhttps://doi.org/10.1190/1.1816383 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Permalink: https://doi.org/10.1190/1.1816383FiguresReferencesRelatedDetailsCited byAn Improved 3D...

We present an iterative algorithm for inverting 3-D pole-pole DC resistivity data. The utilizes AIM (approximate inverse mapping) formalism and inversions are carried out by performing updates in both model space (AIM—MS) data (AIM—DS) using approximate mapping with exact forward mapping. In the mapping, potential anomaly is expressed as a depth integral of logarithmic conductivity perturbation convolved horizontally known kernel. Fourier transforming equation decouples wavenumber components...

We present a binary inversion algorithm for inverting gravity data in salt imaging. The density contrast is restricted to being one of two possibilities: either zero or one, where represents the value expected at given depth. designed easily incorporate known information, and overcome difficulties imaging associated with nil zones. problem may be formulated as general inverse which piecewise constant constructed an indirect means identifying boundary. Difficulty arises when body crosses zone...

We have developed a fast algorithm for generating an equivalent source by using wavelet transforms based on orthonormal, compactly supported wavelets. apply 2D transform to each row and column of the coefficient matrix subsequently threshold transformed generate sparse representation in domain. The then uses this construct directly Performing inverse yields space Using upward continuation total-field magnetic data between uneven surfaces as examples, we compared approach with direct solution...

We studied time-lapse gravity surveys applied to the monitoring of an artificial aquifer storage and recovery (ASR) system in Leyden, Colorado. An abandoned underground coal mine has been developed into a subsurface water reservoir. Water from surface sources is injected during winter for retrieval use summer. As key component geophysical ASR system, three microgravity were conducted over course ten months initial water-injection stage. The successfully detected distribution as well its...