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Hunziker, J. (author), Slob, E.C. (author), Irving, J. (author)
Modeling ground penetrating radar (GPR) reflection data on glaciers with methods that require the discretization of the full subsurface domain is extremely computationally expensive because of the combination of a large domain size and the comparatively short wavelength of the signal. To address this issue, we build on and extend a previously...
journal article 2023
document
Hunziker, Jörg (author), Greenwood, Andrew (author), Minato, S. (author), Barbosa, Nicolás Daniel (author), Caspari, Eva (author), Holliger, Klaus (author)
<p>The hydraulic and mechanical characterization of fractures is crucial for a wide range of pertinent applications, such as geothermal energy production, hydrocarbon exploration, &lt;span classCombining double low line"inline-formula"&gt;CO2&lt;/span&gt; sequestration, and nuclear waste disposal. Direct hydraulic and mechanical testing of...
journal article 2020
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Draganov, D.S. (author), Hunziker, J.W. (author), Heller, H.K.J. (author), Gutkowski, Karin (author), Marte, Fernando (author)
Artworks are an inseparable part of the cultural heritage of societies and provide us with a unique look at cultural developments through time and space. For the best possible conservation, it is paramount to know the constituent materials, condition, and construction techniques of the objects (e.g. painting on wood, fresco, sculpture). Such...
journal article 2018
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Weemstra, C. (author), Draganov, D.S. (author), Ruigrok, E.N. (author), Hunziker, J.W. (author), Gomez, Martin (author), Wapenaar, C.P.A. (author)
Obtaining new seismic responses from existing recordings is generally referred to as seismic interferometry (SI). Conventionally, the SI responses are retrieved by simple crosscorrelation of recordings made by separate receivers: one of the receivers acts as a ‘virtual source’ whose response is retrieved at the other receivers.When SI is applied...
journal article 2017
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Weemstra, C. (author), Draganov, D.S. (author), Ruigrok, E.N. (author), Hunziker, J.W. (author), gomez, Martin (author), Wapenaar, C.P.A. (author)
Obtaining new seismic responses from existing recordings is generally referred to as seismic interferometry (SI). Conventionally, these seismic interferometric responses are retrieved by simple crosscorrelation of recordings made<br/>by separate receivers: a first receiver acts as a 'virtual source' whose response is retrieved at the other...
abstract 2016
document
Hunziker, Jürg (author), Thorbecke, J.W. (author), Brackenhoff, J.A. (author), Slob, E.C. (author)
Marine controlled-source electromagnetic reflection responses can be retrieved by interferometry. These reflection responses are free of effects related to the water layer and the air above it and do not suffer from uncertainties related to the source position and orientation. Interferometry is a data-driven process requiring proper sampling of...
journal article 2016
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Boullenger, B. (author), Hunziker, J.W. (author), Draganov, D.S. (author)
Seismic interferometry (SI) allows retrieval of virtual-source responses at positions of receivers, where no actual source is shot, by cross-correlating (CC) the seismic responses between receivers. The theory requires a boundary of subsurface sources to retrieve the surface reflection response. With reflection data acquired with both sources...
conference paper 2015
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Hunziker, J.W. (author), Thorbecke, J.W. (author), Slob, E.C. (author)
We exploit the randomness of a genetic inversion algorithm to map the global minimum of the solution space of Controlled-Source Electromagnetic inversion problems. In this study, we focus on the information content that vertical electric or magnetic receivers could add to solve for anisotropic conductivities of the subsurface. By analyzing the...
conference paper 2015
document
Slob, E.C. (author), Hunziker, J.W. (author), Thorbecke, J.W. (author), Wapenaar, C.P.A. (author)
conference paper 2014
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Hunziker, J.W. (author), Thorbecke, J.W. (author), Slob, E.C. (author)
conference paper 2014
document
Hunziker, J.W. (author), Thorbecke, J.W. (author), Slob, E.C. (author)
We determined that the electromagnetic vertical transverse isotropic response in a layered earth can be obtained by solving two equivalent scalar equations, which were for the vertical electric field and for the vertical magnetic field, involving only a scalar global reflection coefficient. Besides the complete derivation of the full...
journal article 2014
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Grobbe, N. (author), Hunziker, J.W. (author), Slob, E.C. (author)
The seismoelectric effect can be of importance for hydrocarbon exploration as it is complementary to conventional seismics. Besides enabling seismic resolution and electromagnetic sensitivity at the same time, the seismoelectric method can also provide us with additional, high-value information like porosity and permeability. However, very...
conference paper 2014
document
Hunziker, J.W. (author), Thorbecke, J.W. (author), Slob, E.C. (author)
In an inversion for the subsurface conductivity distribution using frequency-domain Controlled-Source Electromagnetic data, various amounts of horizontal components may be included. We investigate which combination of components are best suited to invert for a vertical transverse isotropic (VTI) subsurface. We do this by probing the...
conference paper 2014
document
Schaller, A.M. (author), Hunziker, J.W. (author), Streich, R. (author), Drijkoningen, G.G. (author)
We investigate potential benefits of measuring the vertical electric field component in addition to the routinely measured horizontal electric field components in onshore time-lapse controlled-source electromagnetics. Synthetic electromagnetic data based on a model of the Schoonebeek onshore oil field are used. We confirm that the vertical...
conference paper 2014
document
Hunziker, J.W. (author), Slob, E.C. (author), Wapenaar, C.P.A. (author)
Interferometry by multidimensional deconvolution for marine Controlled-Source Electromagnetics can suppress the direct field and the airwave in order to increase the detectability of the reservoir. For monitoring, interferometry by multidimensional deconvolution can increase the source repeatability. We give an overview over the method and...
conference paper 2014
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Hunziker, J.W. (author), Slob, E.C. (author), Fan, Y. (author), Snieder, R. (author), Wapenaar, C.P.A. (author)
We use interferometry by multidimensional deconvolution in combination with synthetic aperture sources in 3D to suppress the airwave and the direct field, and to decrease source uncertainty in marine Controlled-Source electromagnetics. We show with this numerical study that the method works for very large receiver spacing distances, even though...
conference paper 2013
document
Hunziker, J.W. (author), Slob, E.C. (author), Fan, Y. (author), Snieder, R. (author), Wapenaar, C.P.A. (author)
With interferometry applied to controlled-source electromagnetic data, the direct field and the airwave and all other effects related to the air-water interface can be suppressed in a data-driven way. Interferometry allows for retreival of the scattered field Green’s function of the subsurface or, in other words, the subsurface reflection...
journal article 2013
document
Hunziker, J.W. (author), Slob, E.C. (author), Fan, Y. (author), Snieder, R. (author), Wapenaar, C.P.A. (author)
Interferometry by multidimensional deconvolution applied to Controlled-Source Electromagnetic data replaces the medium above the receivers by a homogeneous halfspace, suppresses the direct field and redatums the source positions to the receiver locations. In that sense, the airwave and any other interactions of the signal with the air-water...
conference paper 2012
document
Hunziker, J.W. (author)
In marine Controlled-Source Electromagnetics, a boat tows an electric source, whose signal is travelling on various paths to the receiver stations at the ocean bottom. Unfortunately, the signal does not only travel via the subsurface to the receivers, but also directly through the water and via the air-water interface. Signals travelling on the...
doctoral thesis 2012
document
Fan, Y. (author), Snieder, R. (author), Slob, E.C. (author), Hunziker, J.W. (author), Singer, J. (author), Sheiman, J. (author), Rosenquist, M. (author)
Controlled-source electromagnetics (CSEM) has been used as a derisking tool in the hydrocarbon exploration industry. We apply the concept of synthetic aperture to the lowfrequency electromagnetic field in CSEM. Synthetic aperture sources have been used in radar imaging for many years. Using the synthetic aperture concept, big synthetic sources...
journal article 2012
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