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Xue, Guoqiang; Yin, Changchun; Macnae, James; Gelius, Leiv-J. & Hu, Xiangyun
(2024).
Geophysics for critical minerals - Introduction.
Geophysics.
ISSN 0016-8033.
89(1).
doi:
10.1190/geo2023-1117-spseintro.1.
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Greiner, Thomas Larsen; Kolbjørnsen, Odd; Lie, Jan Erik; Nilsen, Espen Harris; Evensen, Andreas Kjelsrud & Gelius, Leiv-J.
(2019).
Cross-streamer wavefield interpolation using deep convolutional neural network.
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Slang, Sigmund; Sun, Jing; Elboth, Thomas; McDonald, Steven & Gelius, Leiv-J.
(2019).
Using Convolutional Neural Networks for Denoising and Deblending of Marine Seismic Data.
EAGE Expanded Abstracts.
doi:
10.3997/2214-4609.201900844.
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Tømmerbakke, Ronny; Johansen, Tor Arne; Ruud, Bent Ole & Gelius, Leiv-J.
(2018).
Flexural Wave Attenuation in X-T
Domain by Complementary Ensemble Empirical Mode Decomposition.
Show summary
Introduction
Seismic surveying in polar regions are obstructed by a number factors and acquiring seismic data on frozen surface is commonly thought to be the best option with a stable surface to operate on. Acquiring on frozen sea ice also enables you to obtain a continuous seismic profile from land to sea. When acquiring on sea ice we get data contaminated by the flexural wave, masking the underlying reflections by both high amplitude and dispersive nature. Many methods to suppress the flexural wave have been proposed, in both acquisition and processing of the data. We propose a methodology based on ensemble empirical mode decomposition (EEMD) in space-time (x-t) domain to separate the flexural wave from the reflections.
EEMD
Empirical mode decomposition (EMD) is a data driven and adaptive decomposition of data to split the data into a series of intrinsic mode functions (IMF) representing different oscillations within the dataset. Originally, EMD struggled with mode mixing where frequency content split in various IMFs. EEMD was developed to improve performance with various levels of white noise added to create ensembles of IMFs and means of the ensembles are used as a final IMF output. The introduction of white noise means weak reflections can be masked and thorough testing is needed to avoid too high levels of white noise.
Results
Synthetic data containing flexural wave noise and reflections show good separation of flexural wave and reflections when reflections are nmo-corrected and in space-time (x-t) domain. Field data with geophones on sea ice surface and detonating cord as source with water depths ranging from zero to 50 m show similar separation of reflections and flexural wave. The field data contain shallow high velocity layers reverberating as multiples in the seismic record, which EEMD can similarly remove. In order to guide the velocity analysis needed to nmo-correct records pre-EEMD, sparse hydrophone recordings below sea ice where data is less affected by the flexural wave are used. Comparison with other methods of flexural wave removal show a better attenuation.
Conclusion
Implementing EEMD in x-t domain on nmo-corrected data we obtain a good separation of the wanted reflection signal and unwanted flexural wave. The EEMD methodology is easy to implement and improve the reliability of seismic data acquired on sea ice.
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Tømmerbakke, Ronny; Johansen, Tor Arne; Gelius, Leiv-J. & Ruud, Bent Ole
(2018).
Ensemble Empirical Mode Decomposition in X-T domain: A novel
approach to improve data quality in seismic acquisition on sea-ice.
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Shantsev, Daniil; Babakhani, A.; Gelius, Leiv-J. & Nerland, E.A.
(2018).
How Repeatable 4D CSEM Surveys Need To Be?
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Gelius, Leiv-J.
(2018).
Presentation of geophysical research activities at the University of Oslo.
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Zhao, Hao; Gelius, Leiv-J. & Tygel, Martin
(2017).
Pre-stack Fourier Mixed-Domain (FMD) Depth Migration.
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Zhao, Hao; Gelius, Leiv-J. & Tygel, Martin
(2015).
A New Generalized Screen Propagator for Wave Equation Depth Migration.
EAGE Expanded Abstracts.
doi:
10.3997/2214-4609.201412786.
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Faccipieri, J. H.; Gelius, Leiv-J. & Tygel, Martin
(2013).
Diffraction separation based on perturbed CRS attributes.
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Gelius, Leiv-J. & Tygel, Martin
(2013).
The cost function used in 3D mCSEM inversion – is the Born approximation valid?
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Gelius, Leiv-J. & Tygel, Martin
(2013).
The 2D incremental ray-propagator.
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Berthelot, Angélique; Solberg, Anne H Schistad; Morisbak, Erlend & Gelius, Leiv-J.
(2012).
3D segmentation of salt using texture attributes.
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Asgedom, Endrias Getachew; Gelius, Leiv-J.; Faccipierri, Jorge H. & Tygel, Martin
(2012).
2-D pre- and post-stack diffraction separation and imaging.
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Solberg, Anne H Schistad; Gelius, Leiv-J.; Jensen, Are Charles & Heeremans, Michel
(2012).
Phase attributes by considering local 3D structure orientation.
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Asgedom, Endrias Getachew; Gelius, Leiv-J. & Tygel, Martin
(2011).
Diffraction separation using the CRS technique: A field data application.
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Gelius, Leiv-J.
(2010).
Diffraction-limited imaging and beyond.
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Gelius, Leiv-J.
(2009).
Time-reversal and super-resolution in case of two transceiver arrays: generalized DORT.
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Gelius, Leiv-J.
(2007).
A rock-physics approach to Sea Bed Logging (SBL) modelling/inversion.
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Jensen, Erling Hugo; Johansen, Tor Arne & Gelius, Leiv-J.
(2006).
Læreverk og læringssystem i ett. En geovitenskapelig læringsplattform. UniGEM.
Forum for fjernundervisning.
ISSN 1503-7770.
1.
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Gelius, Leiv-J.
(2003).
Introduction to seismic processing.
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Sjøberg, Thomas A.; Gelius, Leiv-J. & Lecomte, I.
(2003).
2-D deconvolution of seismic image blur. doi: 10.1190/1.1817453.
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Gelius, Leiv-J.; Lecomte, I. & Hamran, Svein-Erik
(2002).
The concept of Local Parabolic-Wave Imaging (LpI)in PSDM doi: 10.1190/1.1816862.
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Hamran, Svein-Erik; Lecomte, I. & Gelius, Leiv-J.
(2002).
GPR processing using local Plane-wave Imaging.
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Lecomte, I.; Hamran, Svein-Erik; Tabti, Hocine & Gelius, Leiv-J.
(2001).
New Insights in migration Through analogies between Generalized Diffraction Tomography and Synthetic Aperture Radar. doi: 10.1190/1.1816279.
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Gelius, Leiv-J. & Lecomte, Isabelle
(1998).
The resolution function in linearized Born and Kirchhoff Inversion.
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Lecomte, Isabelle & Gelius, Leiv-J.
(1998).
Have a look at the resolution function of prestack depth migration for any model, survey and wavefields. doi: 10.1190/1.1820082.
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Gelius, Leiv-J.; Westerdahl, Harald & Kong, F.N.
(1997).
Modelling and imaging within the diffraction limit with application in engineering geophysics.
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Johansen, Ingvild & Gelius, Leiv-J.
(1995).
Maximum likelihood object location employing magnetometer and radar surface data.
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Stamnes, Jakob J.; Wedberg, Torolf C. & Gelius, Leiv-J.
(1995).
Tomographic Reconstruction From Real Data.
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Gelius, Leiv-J. & Rathy, Sanchya
(2020).
Separation of Diffractions from Reflections by the Double Square Root Operator.
7Letras.
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Thorkildsen, Vemund Stenbekk; Gelius, Leiv-J.; Harris Nilsen, Espen; Kjelsrud Evensen, Andreas & Lie, Jan Erik
(2019).
Separation of diffractions by diffraction-stacking and Plane-Wave Destruction filtering.
7Letras.
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Losnedahl, Sander Wågønes; Gelius, Leiv-J.; Sollner, Walter; Asgedom, Endrias Getachew & Orji, Okwudili Chuks
(2019).
Marine Vibrators: Synthetic Data Study.
7Letras.
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Slang, Sigmund; Gelius, Leiv-J. & Elboth, Thomas
(2019).
Attenuation of Seismic Interference Noise with Convolutional Neural Networks.
7Letras.
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Turquais, Pierre; Sollner, Walter; Asgedom, Endrias Getachew; Gelius, Leiv-J. & Maupin, Valerie
(2018).
Dictionary learning and sparse representations for denoising and reconstruction of marine seismic data.
7Letras.
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Waldeland, Anders U.; Solberg, Anne H Schistad & Gelius, Leiv-J.
(2018).
Seismic image analysis for applications related to iterative 3D velocity model building.
7Letras.
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Grønhaug, Elise; Gelius, Leiv-J. & Elboth, Thomas
(2018).
Investigate noise attenuation by slope-preserving filtering.
7Letras.
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Ordonez, Alba; Söllner, Walter; Klüver, Tilman & Gelius, Leiv-J.
(2016).
Subsurface imaging using multiples from amplitude-normalized separated wavefields: Application to marine towed-streamer data.
7Letras.
Show summary
POPULAR SCIENCE SUMMARY:
Imaging the subsurface is part of the process used in the interpretation of geological
structures that may potentially contain natural resources, such as oil and gas. These
subsurface images are mainly generated from seismic data acquired in marine
environment. Imaging is traditionally applied on seismic data only composed of primary
reflections, which are events reflected once in the subsurface and then returned to the
acquisition level. Multiple reflections, which bounce at least twice in the subsurface, are
commonly treated as noise and suppressed before imaging. However, multiple reflections
have the capability of illuminating subsurface points that primaries cannot reach.
Multiples also contain smaller reflection angles than primaries. These features can
therefore be exploited to improve the image quality and the information content of the
subsurface.
Based on seismic data acquired with multicomponent streamers comprising pressure and
vertical velocity sensors, the PhD student Alba Ordoñez Adellach proposes a new tool for
simultaneously imaging primary and multiple reflections. The main prerequisite for the
approach is the ability to separate the pressure and vertical velocity recordings into their
up- and downgoing components. The upgoing component of the pressure and the
downgoing component of the vertical velocity, both of them composed of primary and
multiple reflections, are combined to retrieve the reflection response of the subsurface.
This is mathematically accomplished by solving an integral equation for every image
point. The new imaging approach was successfully applied on several synthetic and field
data examples.
This doctoral thesis was carried out at the Department of Geosciences, University of Oslo
in collaboration with PGS Geophysical AS.
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Gebregergs, Hagos G.; Gelius, Leiv-J. & Maupin, Valerie
(2016).
Compensation of absorption effects in seismic data.
7Letras.
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Magnussen, Fredrik; Gelius, Leiv-J. & Sanches, Charlotte
(2015).
Deblending of seismic multi-component data.
7Letras.
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Babakhani, Amir; Gelius, Leiv-J.; Shantsev, Daniil & Maupin, Valerie
(2015).
Repeatabiliy and Detectability Requirements for 4D CSEM surveys.
7Letras.
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Grendaite, Milda; Gelius, Leiv-J. & Elboth, Thomas
(2014).
Identifying Seismic Interference Noise based on Local Dip Filtering.
7Letras.
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Fetene, Deneke Admasu; Gelius, Leiv-J. & Vinje, Vetle
(2014).
A noise model for shallow water North Sea.
7Letras.
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Umar, Muhammad; Gelius, Leiv-J. & Øverås, Rune
(2014).
Separation and attenuation of diffractions and their multiples.
7Letras.
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Haghighi, Elyas; Gelius, Leiv-J.; Elboth, Thomas & Sanches, Charlotte
(2014).
Characterizing Seismic Interference from Seismic Multi-component data.
7Letras.
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Asgedom, Endrias Getachew; Gelius, Leiv-J.; Austeng, Andreas & Holm, Sverre
(2012).
On the use of super-resolution algorithms in seismic: Application within diffraction separation and imaging.
7Letras.
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Orji, Okwudili Chuks; Sollner, Walter & Gelius, Leiv-J.
(2012).
Sea surface height estimation for dual-sensor towed streamer.
7Letras.
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Mahmoud, Uzma; Gelius, Leiv-J. & Elboth, Thomas
(2012).
Investigating different approaches of denoising seismic data.
7Letras.
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Lindstrøm, Pia M.; Gelius, Leiv-J. & Zheng, Haishan
(2012).
Diffracted noise attenuation in seismic data.
7Letras.
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Javed, Muhammad Waqas & Gelius, Leiv-J.
(2012).
Separation of reflections from diffractions using the CRS-technique.
7Letras.
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Storbakk, Steffen; Gelius, Leiv-J.; Sanches, Charlotte & Rieder, Mark
(2012).
De-noising of marine seismic data.
7Letras.
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Jensen, Erling Hugo; Johansen, Tor Arne & Gelius, Leiv-J.
(2011).
Methods for improving production of elastic, electric and reservoir properties.
Universitetet i Oslo.
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Saeed, Baseem; Gelius, Leiv-J. & Hoeber, Henning
(2011).
De-noising Seismic Data by Empirical Mode Decomposition.
7Letras.
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Hamid, Abdul; Gelius, Leiv-J. & Klüver, Tilman
(2011).
Comparison/Sensitivity Analysis of Various Deghosting Methods.
7Letras.
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Li, Miao; Gelius, Leiv-J. & Sandvin, Ottar
(2010).
Fresnel-based infill analysis and image quality.
7Letras.
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Wang, Zhong; Gelius, Leiv-J. & Kong, Fannian
(2009).
Investigating the Electric Properties of a Silicliclastic reservoir based on rock-physics modelling and Laboratory experiments.
7Letras.
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Presterud, Ida Vik; Gelius, Leiv-J. & Li, Xia-Ping
(2009).
Time frequency de-noising of seismic data.
7Letras.
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Orji, Okwudili Chuks; Sollner, Walter & Gelius, Leiv-J.
(2009).
Sea imaging from a dual sensor streamer data: A feasibility study.
7Letras.
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Yaqoob, Muhammad Junaid; Gelius, Leiv-J.; Kaschwich, Tina & Lecomte, Isabelle
(2009).
Modeling by demigration: A feasibility study.
7Letras.
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Hofstad, Marcus; Gelius, Leiv-J. & Austeng, Andreas
(2008).
Time-reversal imaging.
7Letras.
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Raja, Usman Zaheer; Gelius, Leiv-J. & Sandvin, Ottar
(2008).
Use of Multiples in VSP Depth Imaging.
7Letras.
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Sultan, Iftikhar; Gelius, Leiv-J. & Vinje, Vetle
(2008).
The sensitivity of residual moveout (RMO) on migration parameters.
7Letras.
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Stensbye, Lars & Gelius, Leiv-J.
(2007).
Processing of a regional deep seismic profile from the South-Western Barents Sea.
7Letras.
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Gelius, Leiv-J. & Westerdahl, Harald
(2006).
SBL imaging. A feasibility study.
Norwegian Geotechnical Institute (NGI).
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Laurain, Renaud; Vinje, Vetle & Gelius, Leiv-J.
(2006).
Simulation and correction of amplitude anomalies in 3D seismic data.
7Letras.
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Møllerup Skaten, Maren Kristin; Nystuen, Johan Petter & Gelius, Leiv-J.
(2006).
The Lillehammer Submarine Fan Complex.
7Letras.
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Gelius, Leiv-J.
(2005).
SBL - reflection study. Multicomponent processing of EM data.
Norwegian Geotechnical Institute (NGI).
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Hellman, Thomas & Gelius, Leiv-J.
(2005).
Fresnel aperture pre-stack depth migration.
7Letras.
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Gelius, Leiv-J.
(2002).
Guide Wave Monitoring of Oil Production. Performance test of the FDFD-method.
Norwegian Geotechnical Institute (NGI).
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Sjøberg, Thomas; Gelius, Leiv-J. & Lecomte, Isabelle
(2002).
Deconvolution of seismic images based on image processing techniques.
7Letras.
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Gelius, Leiv-J.
(2001).
2-D electromagnetic wave-equations.
Norwegian Geotechnical Institute (NGI).
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Gelius, Leiv-J.
(2001).
Frequency domain modelling.
Norwegian Geotechnical Institute (NGI).
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Gelius, Leiv-J. & Kong, Fannian
(2001).
Guide Wave Monitoring of Oil Production. 1-D monochromatic EM-wave modelling.
Norwegian Geotechnical Institute (NGI).
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Gelius, Leiv-J. & Kong, Fannian
(2001).
Guide Wave Monitoring of Oil Production. Frequency domain modelling. .
Norwegian Geotechnical Institute (NGI).
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Kong, Fannian; Viken, Inge; Gelius, Leiv-J. & Iwe, Harald
(2000).
Guide waves III. Technical development of OWC monitoring tool using guide waves.
Norwegian Geotechnical Institute (NGI).
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Olsen, Heidi J & Gelius, Leiv-J.
(2000).
Use of resolution functions in prestack migration.
7Letras.
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Westerdahl, Harald; Viken, Inge; Gelius, Leiv-J. & Kong, Fannian
(1999).
Seabed Logging. 2D Finite difference modeling and object recognition.
Norwegian Geotechnical Institute (NGI).
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Gelius, Leiv-J.
(1998).
3-D orientation of reflecting planes based on VSP measurements - theoretical study.
Norwegian Geotechnical Institute (NGI).
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Gelius, Leiv-J. & Westerdahl, Harald
(1998).
Tunnel seismic. Inversion of image point transformed VSP data - a synthetic example.
Norwegian Geotechnical Institute (NGI).
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Linnestad, Brita & Gelius, Leiv-J.
(1998).
Curved ray tomography with Fermat stabilizer.
7Letras.
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Gelius, Leiv-J.
(1997).
High Resolution Seabed Imaging. Acoustic scattering from a sphere.
Norwegian Geotechnical Institute (NGI).
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Gelius, Leiv-J.
(1997).
Studentstøtte tomografi. Teoretisk bakgrunn for stråletomografi.
Norwegian Geotechnical Institute (NGI).
-
Gelius, Leiv-J.
(1997).
High-resolution Seismic Seabed Imaging. Seismic noise computations.
Norwegian Geotechnical Institute (NGI).
-
Gelius, Leiv-J.
(1997).
High resolution Seabed. Acoustic scattering from a cylinder.
Norwegian Geotechnical Institute (NGI).
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Sætermo, Inger Anne F. & Gelius, Leiv-J.
(1994).
Target characterization: A comparison between diffraction tomography and maximum likelihood estimation.
Norwegian Institute of Technology (NTH).
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Gelius, Leiv-J.
(1992).
Asymptotic diffraction theory with applications in tomography. Dr.techn. thesis.
NTH.