Seismic wavefield polarization – Part I: Describing an elliptical polarized motion, a review of motivations and methods

Labonne, Claire; Sèbe, Olivier; Gaffet, Stéphane

doi:10.1051/e3sconf/20161206001

Cited by 5 publications

(3 citation statements)

References 6 publications

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“…The mine maintains significant infrastructure and is now transitioning into scientific exploration. The Seruci 1 shaft is presently being adapted for a 350 m vertical cryogenic column, required for the 40 Ar distiller for the ARIA project [59]. This requires an upgraded bearing framework that will be able to hold more than one column -for this reason, it is under consideration as a potential distributed vertical arm of the ELGAR detector at reduced cost.…”

Section: Sardinia Facilitymentioning

confidence: 99%

Technologies for the ELGAR large scale atom interferometer array

Canuel,

Abend,

Amaro-Seoane

et al. 2020

Preprint

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We proposed the European Laboratory for Gravitation and Atominterferometric Research (ELGAR), an array of atom gradiometers aimed at studying space-time and gravitation with the primary goal of observing gravitational waves (GWs) in the infrasound band with a peak strain sensitivity of 3.3 × 10 −22 / √ Hz at 1.7 Hz. In this paper we detail the main technological bricks of this large scale detector and emphasis the research pathways to be conducted for its realization. We discuss the site options, atom optics, and source requirements needed to reach the target sensitivity. We then discuss required seismic isolation techniques, Gravity Gradient Noise reduction strategies, and the metrology of various noise couplings to the detector. 42 7.1 Couplings of rotations, gravity gradients, beam misalignment and beam pointing jitter to the initial position and velocity and to the gravitational acceleration.

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Section: Sardinia Facilitymentioning

confidence: 99%

Technologies for the ELGAR large scale atom interferometer array

Canuel,

Abend,

Amaro-Seoane

et al. 2020

Preprint

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“…Numerous fields of study share this need. In the following, a full parameter system for seismology will be proposed based on the conclusions from [6] reviewing different parameter systems.…”

Section: Introductionmentioning

confidence: 99%

Seismic wavefield polarization – Part II: Definition of a parameter system in three-dimensional (3D) space, example case review using LSBB seismic station data

et al. 2016

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Abstract.A full polarization parameter system in 3D space is presented to characterize the state of polarization of a seismic wavefield and to parametrize any type of elliptical polarized seismic wave including extreme linear and circular polarizations. This parameter system does not require the a-priori knowledge of the orientation of the polarization plane and provides access to all parameters required in most polarization studies. Two groups of angular and vectorial parameters are defined, which can be easily related to one another. The knowledge of particle motion polarization opens the field of applications for 3-component seismic records contributing to improvements in phase identification. An example of a time-frequency visualization of the polarization parameters on a teleseimic earthquake recorded at a seismic station of LSBB is presented.

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“…The colour map allows the direction of linear polarization to be represented in a single plot. Previous studies decompose the direction information into different components, for example dip and strike values (Labonne et al, 2016;Li and Crampin, 1991;Pinnegar, 2006) in doing so the polarization required many plots. A similar approach to represent polarization direction was used by Li and Crampin (1991), but for 2 component recordings (purely horizontal; no vertical), and so was not a complete characterization of the wavefield in 3D.…”

Section: Visualizing Principal Componentsmentioning

confidence: 99%

Seismic Polarization in the Near-surface

Griffiths¹

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Seismic polarization is investigated for near-surface reflection data with the development of two processing tools. The first tool is a method of visualizing polarization states.Principal Component Analysis (PCA) has been applied to seismic data to study polarization before, but this is the first time a red-blue-green (RGB) colour map has been used to visualize the analysis output. The new colour map allows the direction of vectors to be displayed on a single plot, instead of decomposing the direction information into different components. This visualization scheme conveys rich information in a concise manner. The second tool is a method to estimate time-dependent time-shift from trace to trace in a shot or common-midpoint (CMP) gather. The method makes use of changes in the phase content of the two signals, exploiting a well known property of the Fourier Transform. To estimate the phase content with time, the Stockwell Transform is used which maps signals into the mixed time-frequency domain. This new method of estimating time-dependent time-shift is more robust to noise, but more vulnerable to aliasing compared to previous time-shift estimation methods such as Dynamic Time Warping. When this new calculation is incorporating into an exisiting velocity independent processing framework, zero-offset sections can be produced in a much less labour intensive manner compared to the Semblance-Normal Moveout approach. This also serves as the first example of velocity independent seismic imaging applied to near-surface reflection data. Combining these processing tools allows for the polarization to be visualized on the scale of survey, and the resulting polarization from different source orientation can be compared conveniently.iv

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Seismic wavefield polarization – Part I: Describing an elliptical polarized motion, a review of motivations and methods

Cited by 5 publications

References 6 publications

Technologies for the ELGAR large scale atom interferometer array

Technologies for the ELGAR large scale atom interferometer array

Seismic wavefield polarization – Part II: Definition of a parameter system in three-dimensional (3D) space, example case review using LSBB seismic station data

Seismic Polarization in the Near-surface

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