Leonardo Uieda

Leonardo Uieda
University of Liverpool | UoL · Department of Earth, Ocean and Ecological Sciences

PhD

About

53
Publications
31,472
Reads
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1,476
Citations
Citations since 2016
20 Research Items
1364 Citations
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
Introduction
I'm a geophysicist specializing in mathematical and computational methods for determining the inner structure of the Earth from physical observations, like disturbances in the Earth's gravity and magnetic fields. I work on a range of open-source software projects in Python and C, including Fatiando a Terra, Tesseroids, and PyGMT. I'm an advocate for openness in the scientific process and the adoption of best practices in computational research.
Additional affiliations
February 2017 - August 2019
University of Hawaiʻi at Mānoa
Position
  • Researcher
February 2014 - February 2018
Rio de Janeiro State University
Position
  • Professor
Description
  • I'm responsible for the undergraduate Geophysics and Numerical Methods courses and the Laboratory of Exploration Geophysics (LAGEX). I'm currently on leave for a 1-2 year visiting researcher/postdoc position at the University of Hawaii.
Education
November 2011 - April 2016
Observatório Nacional
Field of study
  • Geophysics
March 2010 - October 2011
Observatório Nacional
Field of study
  • Geophysics
September 2008 - June 2009
York University
Field of study
  • Earth Science

Publications

Publications (53)
Article
DOWNLOAD PDF + SOURCE CODE: http://www.leouieda.com/papers/paper-tesseroids-2016.html We present the open-source software Tesseroids, a set of command-line programs to perform the forward modeling of gravitational fields in spherical coordinates. The software is implemented in the C programming language and uses tesseroids (spherical prisms) for t...
Article
DOWNLOAD PDF AND CODE AT http://www.leouieda.com/papers/paper-moho-inversion-tesseroids-2016.html --------------------------- Estimating the relief of the Moho from gravity data is a computationally intensive nonlinear inverse problem. What is more, the modelling must take the Earths curvature into account when the study area is of regional scale...
Article
Full-text available
Verde is a Python library for gridding spatial data using different Green's functions. It differs from the radial basis functions in scipy.interpolate by providing an API inspired by scikit-learn. The Verde API should be familiar to scikit-learn users but is tweaked to work with spatial data, which has Cartesian or geographic coordinates and multip...
Article
Full-text available
The Generic Mapping Tools (GMT) software is ubiquitous in the Earth and Ocean sciences. As a cross‐platform tool producing high quality maps and figures, it is used by tens of thousands of scientists around the world. The basic syntax of GMT scripts has evolved very slowly since the 1990s, despite the fact that GMT is generally perceived to have a...
Article
The equivalent source technique is a powerful and widely used method for processing gravity and magnetic data. Nevertheless, its major drawback is the large computational cost in terms of processing time and computer memory. We present two techniques for reducing the computational cost of equivalent source processing: block-averaging source locatio...
Preprint
Full-text available
<<< This paper has been submitted for publication in Geophysical Journal International. A preprint version is available on EarthArXiv. >>> We present the gradient-boosted equivalent sources: a new methodology for interpolating very large datasets of gravity and magnetic observations even on modest personal computers, without the high computer memor...
Presentation
Full-text available
We present a new strategy for defining the location of point sources when applying the equivalent sources technique (EQL) for interpolating gravity and magnetic data. It consist in reducing the number of sources while keeping the same accuracy when compared with similar EQL methods. It also reduces the computation time and memory requirements, both...
Presentation
Full-text available
Presented at EGU 2020 (online because of COVID-19), session "G4.3: Acquisition and processing of gravity and magnetic field data and their integrative interpretation". Details some of the work we've been doing in Verde and Harmonica for machine-learning style interpolation with equivalent-sources. In particular, applying state-of-the-art cross-vali...
Article
Full-text available
Scientific software is usually created to acquire, analyze, model, and visualize data. As such,many software libraries include sample datasets in their distributions for use in documentation,tests, benchmarks, and workshops. A common approach is to include smaller datasets in the GitHub repository directly and package them with the source and binar...
Preprint
We present a new methodology to compute the gravitational fields generated by tesseroids (spherical prisms) whose density varies with depth according to an arbitrary continuous function. It approximates the gravitational fields through the Gauss-Legendre Quadrature along with two discretization algorithms that automatically control its accuracy by...
Article
OPEN ACCESS PREPRINT VERSION: https://doi.org/10.31223/osf.io/3548g ------------------- We present a new methodology to compute the gravitational fields generated by tesseroids (spherical prisms) whose density varies with depth according to an arbitrary continuous function. It approximates the gravitational fields through the Gauss-Legendre Quadra...
Poster
Abstract submitted to LAPIS 2019: Inverse methods in Geophysics. We introduce a novel methodology for gravity forward modeling in spherical coordinates using tesseroids (spherical prisms) with variable densities in depth. It builds on previous work by the authors and introduces a new density-based discretization algorithm to ensure the accuracy of...
Preprint
A recent editorial in Nature Methods, “Giving Software its Due”, described challenges related to the development of research software and highlighted, in particular, the challenge of software publication and citation. Here, we call attention to a system that we have developed that enables community-driven software review, publication, and citation:...
Preprint
Full-text available
An efficient forward modeling algorithm for calculation of gravitational fields in spherical coordinates is developed for 3D large‐scale gravity inversion problems. 3D Gauss‐Legendre quadrature (GLQ) is used to calculate the gravitational fields of mass distributions discretized into tesseroids. Equivalence relations in the kernel matrix of the for...
Preprint
Estimating the relief of the Moho from gravity data is a computationally intensive non-linear inverse problem. What is more, the modeling must take the Earths curvature into account when the study area is of regional scale or greater. We present a regularized non-linear gravity inversion method that has a low computational footprint and employs a s...
Article
Full-text available
PREPRINT PDF: https://doi.org/10.31223/osf.io/dzf9j ----------- An efficient forward modeling algorithm for calculation of gravitational fields in spherical coordinates is developed for 3D large‐scale gravity inversion problems. 3D Gauss‐Legendre quadrature (GLQ) is used to calculate the gravitational fields of mass distributions discretized into t...
Article
FREE PDF (open access): http://dx.doi.org/10.1190/tle36020179.1 Links to open source code at http://www.leouieda.com/papers/nmo-tutorial.html Open any text book about seismic data processing and you will inevitably find a section about the normal moveout (NMO) correction. When applied to a common midpoint (CMP) section, the correction is suppose...
Article
PDF available at: http://www.pinga-lab.org/papers/paper-quadrilatero2-2016.html Airborne gravity gradiometry data have been recently used in mining surveys to map the 3D geometry of ore deposits. This task can be achieved by different gravity-gradient inversion methods, many of which use a voxel-based discretization of the Earth's subsurface. To p...
Code
Fatiando a Terra (Portuguese for Slicing the Earth) is an open-source Python toolkit for modeling and inversion in geophysics. It provides an easy and flexible way to perform and implement geophysical data analysis. Official website and documentation: http://www.fatiando.org DOI for this release: http://dx.doi.org/10.5281/zenodo.49087 Main changes...
Code
Fatiando a Terra (Portuguese for Slicing the Earth) is an open-source Python toolkit for modeling and inversion in geophysics. It provides an easy and flexible way to perform and implement geophysical data analysis. Official website and documentation: http://www.fatiando.org Main changes to version 0.5: http://www.fatiando.org/changelog.html#versio...
Article
Full-text available
We have developed a fast total-field anomaly inversion to estimate the magnetization direction of multiple sources with approximately spherical shapes and known centres. Our method is an overdetermined inverse problem that can be applied to interpret multiple sources with different but homogeneous magnetization directions. It requires neither the p...
Code
A collection of command-line programs for modeling the gravitational potential, acceleration, and gradient tensor. Tesseroids supports models and computation grids in Cartesian and spherical coordinates. Official website and documentation: http://tesseroids.leouieda.com/ This is the first release after the code was ported from Python to C. It was d...
Code
A collection of command-line programs for modeling the gravitational potential, acceleration, and gradient tensor. Tesseroids supports models and computation grids in Cartesian and spherical coordinates. Official website and documentation: http://tesseroids.leouieda.com/ Changes to version 1.1.1: Minor release for bug fixes: * BUG fix: Wrong result...
Code
A collection of command-line programs for modeling the gravitational potential, acceleration, and gradient tensor. Tesseroids supports models and computation grids in Cartesian and spherical coordinates. Official website and documentation: http://tesseroids.leouieda.com/ This was the final version of the software that accompanied my bachelor's thes...
Code
A collection of command-line programs for modeling the gravitational potential, acceleration, and gradient tensor. Tesseroids supports models and computation grids in Cartesian and spherical coordinates. Official website and documentation: http://tesseroids.leouieda.com/ This is the 1.1 release of Tesseroids. See the documentation (http://tesseroid...
Code
A collection of command-line programs for modeling the gravitational potential, acceleration, and gradient tensor. Tesseroids supports models and computation grids in Cartesian and spherical coordinates. Official website and documentation: http://tesseroids.leouieda.com/ The first ever release of Tesseroids. This initial version was made in Python...
Code
A collection of command-line programs for modeling the gravitational potential, acceleration, and gradient tensor. Tesseroids supports models and computation grids in Cartesian and spherical coordinates. Official website and documentation: http://tesseroids.leouieda.com/ Changes to version 1.2.0: * General improvements to the adaptive discretizatio...
Code
Fatiando a Terra (Portuguese for Slicing the Earth) is an open-source Python toolkit for modeling and inversion in geophysics. It provides an easy and flexible way to perform and implement geophysical data analysis. Official website and documentation: http://www.fatiando.org Changes to version 0.3: * New module fatiando.gravmag.normal_gravity * **B...
Code
Fatiando a Terra (Portuguese for Slicing the Earth) is an open-source Python toolkit for modeling and inversion in geophysics. It provides an easy and flexible way to perform and implement geophysical data analysis. Official website and documentation: http://www.fatiando.org This is the first public release of the package.
Article
Full-text available
We have developed a fast total-field anomaly inversion to estimate the magnetization direction of multiple sources with approximately spherical shape and known centres. Our method can be applied to interpret multiple sources with different magnetization directions. It neither requires the prior computation of any transformation like reduction to th...
Article
DOWNLOAD PDF: http://www.pinga-lab.org/papers/paper-quadrilatero-2014.html The Quadrilátero Ferrífero in southeastern Brazil hosts one of the largest concentrations of lateritic iron ore deposits in the world. Our study area is over the southern flank of the Gandarela syncline which is one of the regional synclines of the Quadrilátero Ferrífero. T...
Conference Paper
Full-text available
We developed a method that drastically reduces the number of the source location estimates in Euler deconvolution to only one per anomaly. We use the analytical estimators of the Euler solutions. Our approach consists in detecting automatically the regions of the anomaly producing consistent estimates of the source horizontal coordinates. These reg...
Article
Full-text available
OPEN-ACCESS ARTICLE. DOWNLOAD PDF: http://dx.doi.org/10.1190/tle33040448.1 DOWNLOAD SOURCE: http://www.leouieda.com/papers/paper-tle-euler-tutorial-2014.html In this tutorial, we will talk about a widely used method of interpretation for potential-field data called Euler de-convolution. Our goal is to demonstrate its usefulness and, most importa...
Book
Open licensed (CC-BY) lecture notes in geophysical inverse problems (in Portuguese). Source code: https://github.com/pinga-lab/inverse-problems PDF: http://dx.doi.org/10.6084/m9.figshare.1192984
Article
Full-text available
We have provided supplementary material to our article titled “Estimating the nature and the horizontal and vertical positions of 3D magnetic sources using Euler deconvolution” and whose authors are Felipe F. Melo, Valeria C. F. Barbosa, Leonardo Uieda, Vanderlei C. Oliveira Jr, and João B. C. Silva. In this material, we presented an extra sy...
Article
Full-text available
We have developed a new method that drastically reduces the number of the source location estimates in Euler deconvolution to only one per anomaly. Our method employs the analytical estimators of the base level and of the horizontal and vertical source positions in Euler deconvolution as a function of the x- and y-coordinates of the observations. B...
Article
Full-text available
DOWNLOAD PDF + SOURCE CODE: http://www.pinga-lab.org/papers/paper-polynomial-eqlayer-2013.html We have developed a new cost-effective method for processing large-potential-field data sets via the equivalent-layer technique. In this approach, the equivalent layer is divided into a regular grid of equivalent-source windows. Inside each window, the p...
Conference Paper
>>> PDF and talk recording: http://www.leouieda.com/talks/scipy2013.html <<< Geophysics is the science of using physical observations of the Earth to infer its inner structure. Generally, this is done with a variety of numerical modeling techniques and inverse problems. The development of new algorithms usually involves copy and pasting of code,...
Conference Paper
DOWNLOAD PDF + SLIDES: http://www.leouieda.com/talks/seg-carlos2012.html We have interpreted the airborne gravity gradiometry data from Carajás Mineral Province (CMP), Brazil, by using two different 3D inversion methods. Both inversion methods parameterized the Earth‟s subsurface into prismatic cells and estimate the 3D density-contrast distributi...
Conference Paper
DOWNLOAD PDF: http://www.leouieda.com/talks/seg2012.html We present an improvement to the method of 3D gravity gradient inversion by planting anomalous densities. This method estimates a density-contrast distribution defined on a grid of right-rectangular prisms. Instead of solving large equation systems, the method uses a systematic search algori...
Article
DOWNLOAD PDF + SOURCE CODE: http://www.leouieda.com/papers/paper-planting-anomalous-densities-2012.html We have developed a new gravity gradient inversion method for estimating a 3D density-contrast distribution defined on a grid of rectangular prisms. Our method consists of an iterative algorithm that does not require the solution of an equation...
Article
We provide supplementary material to Uieda and Barbosa (2012). The material included are: (1) plots of the predicted and synthetic gyy and gyz components from the section "Application to synthetic data", (2) plots of the results of the sensitivity analysis to uncertainties in the density-contrast value of the seeds, (3) the contour maps of the synt...
Conference Paper
We present a new gravity gradient inversion method for estimating a 3D density-contrast distribution defined on a grid of prisms. Our method consists of an iterative algorithm that does not require the solution of a large equation system. Instead, the solution grows systematically around user-specified prismatic elements called "seeds". Each seed c...
Conference Paper
This paper is in Portuguese. We have interpreted the airborne gravity gradiometry data from Quadrilátero Ferrífero, an iron ore province in southeastern Brazil. Aiming at retrieving the geometry of the iron body, we have used a fast and novel gravity inversion method for estimating a 3D density-contrast distribution defined on a grid of prisms. Thi...
Conference Paper
This paper presents a novel gravity inversion method for estimating a 3D density-contrast distribution defined on a grid of prisms. Our method consists of an iterative algorithm that does not require the solution of a large equation system. Instead, the solution grows systematically around user-specified prismatic elements called “seeds”. Each seed...
Conference Paper
DOWNLOAD PDF: http://www.leouieda.com/talks/eage2011.html We present a new gravity gradient tensor inversion for estimating a 3D density-contrast distribution defined on a user-specified grid of prisms. Our method consists of an iterative algorithm that does not require the solution of large equation system. Instead, the solution grows systematica...
Conference Paper
Full-text available
We have interpreted the airborne gravity gradiometry data from Quadrilátero Ferr'ifero, an iron ore province in southeastern Brazil. Aiming at retrieving the geometry of the iron body, we have used a fast and novel gravity inversion method for estimating a 3D density-contrast distribution defined on a grid of prisms. This inversion approach combine...
Conference Paper
DOWNLOAD PDF: http://www.leouieda.com/talks/goce2011.html The new observations of GOCE present a challenge to develop new calculation methods that take into account the sphericity of the Earth. We address this problem by using a discretization with a series of tesseroids. There is no closed formula giving the gravitational fields of the tesseroid...
Thesis
DOWNLOAD PDF: http://dx.doi.org/10.6084/m9.figshare.963547 DOWNLOAD SOURCE: https://github.com/leouieda/barchelor-thesis The GOCE satellite mission has the objective of measuring the Earths gravitational field with an unprecedented accuracy through the measurement of the gravity gradient tensor (GGT). The data provided by this mission could be us...

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Projects

Projects (3)
Project
Develop methods for accurate forward modelling of gravitational fields in spherical coordinates. Software that implements these methods is always freely available and open-source.
Project
We are bringing the power of GMT to Python through a wrapper library that relies on the GMT C API. Find out more about the project and how you can get involved at https://www.pygmt.org
Project
Fatiando is a collection of open-source Python packages for Geophysics. Our toolkit includes code for processing geophysical data, forward and inverse modeling, interpolation, and more. ----- https://www.fatiando.org