Three-dimensional (3-D) interactive modelling permits an integrated processing and interpretation... more Three-dimensional (3-D) interactive modelling permits an integrated processing and interpretation of geoid, gravity and magnetic fields, yielding an improved geologic interpretation. Generally 3-D models are constructed by triangulated polyhedra to which constant density and/or induced and remanent susceptibility are assigned. Interactive modifications of model parameters (geometry, density, susceptibility), access to the numerical modelling process, and direct visualization of both calculated
Modern interpretation in geophysics requires an interdisciplinary knowledge, integration and cons... more Modern interpretation in geophysics requires an interdisciplinary knowledge, integration and consideration of ‘state of the art’ information from comprehensive data bases. Towards this end a combination of different geophysical surveys employing seismics, gravity, magnetics, and geoelectrics, together with geological, mineralogical, petrological studies, and results from remote sensing provides new insights into the structures and tectonic evolution of natural deposits and
Modern workflows for construction of 3-D data-constrained Earth’s subsurface models in complex ge... more Modern workflows for construction of 3-D data-constrained Earth’s subsurface models in complex geological environments require sophisticated research software tools capable of handling interdisciplinary data and analysis in both visual and quantitative context. Integration of potential field data – gravity and magnetics – into the model building process is a key component that helps to bridge the gaps in the sparse input data by fitting the modelled response to the measurements. On the basis of IGMAS+ – a free cross-platform potential field modelling software – we show how 3-D model building can be complemented by interactive optimisation (inversion) of the triangulated subsurface model geometry. The optimisation is done by means of Covariance-Matrix-Adaptation Evolution Strategy (CMAES) which proved to be efficient for strongly non-linear problems with high-dimensional parameter space. In order to avoid topology distortions of the triangulated model domain, we use a concept of warping the space containing a model, rather than operating on the model vertices. The space warping implies an elegant solution using a system of virtual elastic springs connecting the lattice nodes. The optimisation workflow is demonstrated on synthetic and real case studies. We also show how an interpreter can interact with the process: visually control and influence the quality of the optimisation on a timeline. The proposed workflow is an efficient tool for automated quick model construction, validation and rebuilding, as well as for testing of multiple modelling hypotheses.
EDV-based interactive modelling and visualization methods have become an essential part in the pr... more EDV-based interactive modelling and visualization methods have become an essential part in the process of construction and analysis of three-dimensional models in Earth sciences. However, dealing with complex geoscience models, existing modeling systems can satisfy the user requirements only inadequately. The modelling program IGMAS (Interactive Gravity and Magnetic Application System) [Gatze et al, 1988] and the visualization program IVIS-3D (IGMAS Visualization in 3D) [Klesper, 1997] were designed to ease interactive modelling projects. The interactive modelling program IGMAS provides numerical simulation by forward modelling, to build and analyse 3D potential field models (gravity, geoid & magnetics). Various functions, an intuitive and easy to use enviroment and the combination of measured and interpreted data allows the flexible creation of different model versions. Up to now missing functionality of interactive 3D-visualization was compensated by a patchwork of different programs or the user had to handle complex visualization systems with a large overhead of functionality. For this reason we decided to create a program which provides enhanced visualization methods within the modelling process. IVIS3D now adapts the capabilities of interactive 3D-visualization with an easy to use graphical user interface to the existing modelling program IGMAS.
Abstract The overall acceptance and easy access to the World Wide Web (WWW) makes it to an intere... more Abstract The overall acceptance and easy access to the World Wide Web (WWW) makes it to an interesting media for the exchange of a wide range of research information. But unfortunately there is no fully functional Internet technique available for real interactive 3D visualisation up to now. The basic WWW concept, high net traffic and slow Internet servers prevent the interactive exchange of large 3D-datasets. Techniques which supports offline rendering may become a solution to work around these problems until more satisfying techniques for interactive work in the WWW are available.
Modelling in 3D on a 2D screen is a difficult endeavour. The outcome depends mainly on how softwa... more Modelling in 3D on a 2D screen is a difficult endeavour. The outcome depends mainly on how software implements modeling-tools. Tools used in the movie industry require a lot of time for user training. Usually geoscientists are specialized in their fields and they are not trained in computer-based interactive 3D modelling. They require simple-to-use modelling strategies, which can be used by geo-experts not familiar with sophisticated 3D manipulators and – most importantly – allow the creation and, most often, handling existing models (e.g., salt structures coming from seismic interpretation). Since models get more and more complex in geometry (e.g., complex multi-z geometries), modelling tools must be designed in a way that model-topology is conserved while constraints are respected, when such tools are applied. Thereby it is important that the tools must guarantee topology conservation, no matter what operations are performed to geo-models. Therefore tools for interactive 3D modelling of potential field data have been rethought and implemented in the IGMAS platform (Alvers et al., 2013; 2014, Lahmeyer et al., 2010). Responding to the question ‘Quo Vadis Inversion?’, this paper presents a new method (based on Alvers et al., 2013; 2014) for an automated interactive 3D-inversion. Thereby the methodology is, to let the user select a certain part of the model, thought to be wrong, by simply opening a box around it and start an automated inversion, which can be watched in (ideally) real time. The new approach is that now users can stop the automated inversion at any time, rewind if required, reset parameters (such as constraints) and rerun the process from there. The aim is to put the geo-expert in the driver’s seat to easily test geological and geophysical hypotheses. Based on a hybrid model (Schmidt et al., 2011) structure consisting of grids, voxel cubes and triangulated surfaces, complex models can be created and modified either interactively or by automated interactive inversion as described below.
<p>We introduce a modelling concept for the construction of 3-D data-constrained su... more <p>We introduce a modelling concept for the construction of 3-D data-constrained subsurface structural density models at different spatial scales: from large-scale models (thousands of square km) to regional (hundreds of square km) and small-scale (tens of square km) models used in applied geophysics. These models are important for understanding the drivers of geohazards, for efficient and sustainable extraction of resources from sedimentary basins such as groundwater, hydrocarbons or deep geothermal energy, as well as for investigation of capabilities of long-term underground storage of gas and radioactive materials.</p><p>The modelling concept involves interactive fitting of potential fields (gravity and magnetics) and their derivatives within IGMAS+ (Interactive Gravity and Magnetic Application System), a well-known software tool with almost 40 years of development behind it. The core of IGMAS+ is the analytical solution of the volume integral for gravity and magnetic effects of homogeneous bodies, bounded by polyhedrons of triangulated model interfaces. The backbone model is constrained by interdisciplinary data, e.g. geological maps, seismic reflection and refraction profiles, structural signatures obtained from seismic receiver functions, local surveys etc. The software supports spherical geometries to resolve the first-order effects related to the curvature of the Earth, which is especially important for large-scale models.</p><p>Currently being developed and maintained at the Helmholtz Centre Potsdam – GFZ German Research Centre, IGMAS+ has a cross-platform implementation with parallelization of computations and optimized storage. The powerful graphical interface makes the interactive modelling and geometry modification process user-friendly and robust. Historically IGMAS+ is free for research and education purposes and has a long-term plan to remain so.</p><p>IGMAS+ has been used in various tectonic settings and we demonstrate its flexibility and usability on several lithospheric-scale case studies in South America and Europe.</p><p>Both science and industry are close to the goal of treating all available geoscientific data and geophysical methods inside a single subsurface model that aims to integrate most of the interdisciplinary measurement-based constraints and essential structural trends coming from geology. This approach presents challenges for both its implementation within the modelling software and the usability and plausibility of generated results, requiring a modelling concept that integrates the data methods in a feasible way together with recent advances in data science methods. As such, we present the future outlook of our modelling concept in regards to these challenges.</p>
... are reported by MARINOVIC & LAHSEN (1984) from the southern part of the Sierra de Moreno ... more ... are reported by MARINOVIC & LAHSEN (1984) from the southern part of the Sierra de Moreno (K/Ar in biotite: 10314 Ma). The "Mid" Cretaceous volcanics underlie with angular unconformity (MUNOZ, ]986) a younger, only slightly warped volcanic sequence (Chile-Alemania Fm ...
London 2013, 75th eage conference en exhibition incorporating SPE Europec, 2013
ABSTRACT We present improved 3D modeling techniques for potential field data. A new 3D-editing co... more ABSTRACT We present improved 3D modeling techniques for potential field data. A new 3D-editing concept makes geometry changes in 3D easier, without the risk of creating inconsistent models with crossing boundaries or holes. Based on the new 3D editor the concept of interactive inversion is introduced. Also spherical modeling avoids incorrect calculations for big regional models. In order to guarantee that the improvements above are applicable in an interactive program we present strategies for big performance improvements. All the techniques described are currently tested and will be implemented in IGMAS+.
Three-dimensional (3-D) interactive modelling permits an integrated processing and interpretation... more Three-dimensional (3-D) interactive modelling permits an integrated processing and interpretation of geoid, gravity and magnetic fields, yielding an improved geologic interpretation. Generally 3-D models are constructed by triangulated polyhedra to which constant density and/or induced and remanent susceptibility are assigned. Interactive modifications of model parameters (geometry, density, susceptibility), access to the numerical modelling process, and direct visualization of both calculated
Modern interpretation in geophysics requires an interdisciplinary knowledge, integration and cons... more Modern interpretation in geophysics requires an interdisciplinary knowledge, integration and consideration of ‘state of the art’ information from comprehensive data bases. Towards this end a combination of different geophysical surveys employing seismics, gravity, magnetics, and geoelectrics, together with geological, mineralogical, petrological studies, and results from remote sensing provides new insights into the structures and tectonic evolution of natural deposits and
Modern workflows for construction of 3-D data-constrained Earth’s subsurface models in complex ge... more Modern workflows for construction of 3-D data-constrained Earth’s subsurface models in complex geological environments require sophisticated research software tools capable of handling interdisciplinary data and analysis in both visual and quantitative context. Integration of potential field data – gravity and magnetics – into the model building process is a key component that helps to bridge the gaps in the sparse input data by fitting the modelled response to the measurements. On the basis of IGMAS+ – a free cross-platform potential field modelling software – we show how 3-D model building can be complemented by interactive optimisation (inversion) of the triangulated subsurface model geometry. The optimisation is done by means of Covariance-Matrix-Adaptation Evolution Strategy (CMAES) which proved to be efficient for strongly non-linear problems with high-dimensional parameter space. In order to avoid topology distortions of the triangulated model domain, we use a concept of warping the space containing a model, rather than operating on the model vertices. The space warping implies an elegant solution using a system of virtual elastic springs connecting the lattice nodes. The optimisation workflow is demonstrated on synthetic and real case studies. We also show how an interpreter can interact with the process: visually control and influence the quality of the optimisation on a timeline. The proposed workflow is an efficient tool for automated quick model construction, validation and rebuilding, as well as for testing of multiple modelling hypotheses.
EDV-based interactive modelling and visualization methods have become an essential part in the pr... more EDV-based interactive modelling and visualization methods have become an essential part in the process of construction and analysis of three-dimensional models in Earth sciences. However, dealing with complex geoscience models, existing modeling systems can satisfy the user requirements only inadequately. The modelling program IGMAS (Interactive Gravity and Magnetic Application System) [Gatze et al, 1988] and the visualization program IVIS-3D (IGMAS Visualization in 3D) [Klesper, 1997] were designed to ease interactive modelling projects. The interactive modelling program IGMAS provides numerical simulation by forward modelling, to build and analyse 3D potential field models (gravity, geoid & magnetics). Various functions, an intuitive and easy to use enviroment and the combination of measured and interpreted data allows the flexible creation of different model versions. Up to now missing functionality of interactive 3D-visualization was compensated by a patchwork of different programs or the user had to handle complex visualization systems with a large overhead of functionality. For this reason we decided to create a program which provides enhanced visualization methods within the modelling process. IVIS3D now adapts the capabilities of interactive 3D-visualization with an easy to use graphical user interface to the existing modelling program IGMAS.
Abstract The overall acceptance and easy access to the World Wide Web (WWW) makes it to an intere... more Abstract The overall acceptance and easy access to the World Wide Web (WWW) makes it to an interesting media for the exchange of a wide range of research information. But unfortunately there is no fully functional Internet technique available for real interactive 3D visualisation up to now. The basic WWW concept, high net traffic and slow Internet servers prevent the interactive exchange of large 3D-datasets. Techniques which supports offline rendering may become a solution to work around these problems until more satisfying techniques for interactive work in the WWW are available.
Modelling in 3D on a 2D screen is a difficult endeavour. The outcome depends mainly on how softwa... more Modelling in 3D on a 2D screen is a difficult endeavour. The outcome depends mainly on how software implements modeling-tools. Tools used in the movie industry require a lot of time for user training. Usually geoscientists are specialized in their fields and they are not trained in computer-based interactive 3D modelling. They require simple-to-use modelling strategies, which can be used by geo-experts not familiar with sophisticated 3D manipulators and – most importantly – allow the creation and, most often, handling existing models (e.g., salt structures coming from seismic interpretation). Since models get more and more complex in geometry (e.g., complex multi-z geometries), modelling tools must be designed in a way that model-topology is conserved while constraints are respected, when such tools are applied. Thereby it is important that the tools must guarantee topology conservation, no matter what operations are performed to geo-models. Therefore tools for interactive 3D modelling of potential field data have been rethought and implemented in the IGMAS platform (Alvers et al., 2013; 2014, Lahmeyer et al., 2010). Responding to the question ‘Quo Vadis Inversion?’, this paper presents a new method (based on Alvers et al., 2013; 2014) for an automated interactive 3D-inversion. Thereby the methodology is, to let the user select a certain part of the model, thought to be wrong, by simply opening a box around it and start an automated inversion, which can be watched in (ideally) real time. The new approach is that now users can stop the automated inversion at any time, rewind if required, reset parameters (such as constraints) and rerun the process from there. The aim is to put the geo-expert in the driver’s seat to easily test geological and geophysical hypotheses. Based on a hybrid model (Schmidt et al., 2011) structure consisting of grids, voxel cubes and triangulated surfaces, complex models can be created and modified either interactively or by automated interactive inversion as described below.
<p>We introduce a modelling concept for the construction of 3-D data-constrained su... more <p>We introduce a modelling concept for the construction of 3-D data-constrained subsurface structural density models at different spatial scales: from large-scale models (thousands of square km) to regional (hundreds of square km) and small-scale (tens of square km) models used in applied geophysics. These models are important for understanding the drivers of geohazards, for efficient and sustainable extraction of resources from sedimentary basins such as groundwater, hydrocarbons or deep geothermal energy, as well as for investigation of capabilities of long-term underground storage of gas and radioactive materials.</p><p>The modelling concept involves interactive fitting of potential fields (gravity and magnetics) and their derivatives within IGMAS+ (Interactive Gravity and Magnetic Application System), a well-known software tool with almost 40 years of development behind it. The core of IGMAS+ is the analytical solution of the volume integral for gravity and magnetic effects of homogeneous bodies, bounded by polyhedrons of triangulated model interfaces. The backbone model is constrained by interdisciplinary data, e.g. geological maps, seismic reflection and refraction profiles, structural signatures obtained from seismic receiver functions, local surveys etc. The software supports spherical geometries to resolve the first-order effects related to the curvature of the Earth, which is especially important for large-scale models.</p><p>Currently being developed and maintained at the Helmholtz Centre Potsdam – GFZ German Research Centre, IGMAS+ has a cross-platform implementation with parallelization of computations and optimized storage. The powerful graphical interface makes the interactive modelling and geometry modification process user-friendly and robust. Historically IGMAS+ is free for research and education purposes and has a long-term plan to remain so.</p><p>IGMAS+ has been used in various tectonic settings and we demonstrate its flexibility and usability on several lithospheric-scale case studies in South America and Europe.</p><p>Both science and industry are close to the goal of treating all available geoscientific data and geophysical methods inside a single subsurface model that aims to integrate most of the interdisciplinary measurement-based constraints and essential structural trends coming from geology. This approach presents challenges for both its implementation within the modelling software and the usability and plausibility of generated results, requiring a modelling concept that integrates the data methods in a feasible way together with recent advances in data science methods. As such, we present the future outlook of our modelling concept in regards to these challenges.</p>
... are reported by MARINOVIC & LAHSEN (1984) from the southern part of the Sierra de Moreno ... more ... are reported by MARINOVIC & LAHSEN (1984) from the southern part of the Sierra de Moreno (K/Ar in biotite: 10314 Ma). The "Mid" Cretaceous volcanics underlie with angular unconformity (MUNOZ, ]986) a younger, only slightly warped volcanic sequence (Chile-Alemania Fm ...
London 2013, 75th eage conference en exhibition incorporating SPE Europec, 2013
ABSTRACT We present improved 3D modeling techniques for potential field data. A new 3D-editing co... more ABSTRACT We present improved 3D modeling techniques for potential field data. A new 3D-editing concept makes geometry changes in 3D easier, without the risk of creating inconsistent models with crossing boundaries or holes. Based on the new 3D editor the concept of interactive inversion is introduced. Also spherical modeling avoids incorrect calculations for big regional models. In order to guarantee that the improvements above are applicable in an interactive program we present strategies for big performance improvements. All the techniques described are currently tested and will be implemented in IGMAS+.
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Papers by Hajo Götze