Advances in long-range GPR systems and their applications to mineral exploration, geotechnical and static correction problems

Francke, Jan; Utsi, Vincent

doi:10.3997/1365-2397.27.1301.29031

Cited by 30 publications

(12 citation statements)

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“…3) Signal: The Blackman-Harris window [39]- [41] was used as the source function f (t, x) = f (t)δ p ( x), i.e., f (t) = 0.359 − 0.488 cos (20πt) + 0.141 cos (40πt) − 0.012 cos (60πt) (25) for t ≤ 0.1 (170 ns), and f (t) = 0, otherwise. This pulse is centered around 10 MHz frequency suitable for cavity detection [27], [39], [42], [43]. The data were gathered covering the time window from t = 0 to T = 1.3 (2.2 µs) at 60 MHz frequency, which was 1.7 relative to the Nyquist rate (NR), i.e., two times the density of sampling points divided by the bandwith of the signal.…”

Section: Numerical Experimentsmentioning

confidence: 99%

Orbiter-to-orbiter tomography: a potential approach for small solar system bodies

Pursiainen

Kaasalainen

2016

IEEE Trans. Aerosp. Electron. Syst.

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The goal of this paper is to advance mathematical and computational methodology for orbiter-to-orbiter radio tomography of small planetary objects. In this study, an advanced full waveform forward model is coupled with a total variation based inversion technique. We use a satellite formation model in which a single unit receives a signal that is transmitted by one or more transponder satellites. Numerical results for a 2D domain are presented.Index Terms-Radio Tomography, Small Planetary Objects, Inverse Problems, Waveform Imaging. t 0 ∇u(τ, x) dτ yields the first order system arXiv:1608.06566v1 [astro-ph.IM]

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Section: Numerical Experimentsmentioning

confidence: 99%

Orbiter-to-orbiter tomography: a potential approach for small solar system bodies

Pursiainen

Kaasalainen

2016

IEEE Trans. Aerosp. Electron. Syst.

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“…Akin to airborne GPR, the radar design is based on the stepped-frequency measurement technique coupled with a linear dipole antenna (Fu et al, 2014). We aim to use a low 20-50 MHz signal frequency in order to maximize the signal penetration depth (Francke and Utsi, 2009;Leucci, 2008;Kofman, 2012) and, thereby, to obtain a global data coverage for the interior part. The main mission objective will be achieved, if the internal macroporosity structures can be detected and mapped.…”

Section: Discussionmentioning

confidence: 99%

“…It also maximizes the power gain of the solar panels and reduces the need for power storage. frequency bellow 100 MHz (Francke and Utsi, 2009;Leucci, 2008;Kofman, 2012). We initially target at 20-50 MHz center frequency in the radar design.…”

Section: Introductionmentioning

confidence: 99%

DISCUS – The Deep Interior Scanning CubeSat mission to a rubble pile near-Earth asteroid

Bambach

Deller

Vilenius

et al. 2018

Advances in Space Research

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We have performed an initial stage conceptual design study for the Deep Interior Scanning CubeSat (DIS-CUS), a tandem 6U CubeSat carrying a bistatic radar as the main payload. DISCUS will be operated either as an independent mission or accompanying a larger one. It is designed to determine the internal macroporosity of a 260-600 m diameter Near Earth Asteroid (NEA) from a few kilometers distance. The main goal will be to achieve a global penetration with a low-frequency signal as well as to analyze the scattering strength for various different penetration depths and measurement positions. Moreover, the measurements will be inverted through a computed radar tomography (CRT) approach. The scientific data provided by DISCUS would bring more knowledge of the internal configuration of rubble pile asteroids and their collisional evolution in the Solar System. It would also advance the design of future asteroid deflection concepts. We aim at a single-unit (1U) radar design equipped with a half-wavelength dipole antenna. The radar will utilize a stepped-frequency modulation technique the baseline of which was developed for ESA's technology projects GINGER and PIRA. The radar measurements will be used for CRT and shape reconstruction. The CubeSat will also be equipped with an optical camera system and laser altimeter to support navigation and shape reconstruction. We provide the details of the measurement methods to be applied along with the requirements derived of the known characteristics of rubble pile asteroids. Additionally, an initial design study of the platform and targets accessible within 20 lunar distances is presented.

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“…For GPR the electric conductivity and dielectric permittivity are of importance. The magnetic permeability effect on the propagation of GPR wave is negligible in most geologic environments (Francke and Utsi, 2009). GPR is most effective in low-loss materials such as dry sand or gravel, that have few ions in the pore water or material structure.…”

Section: Electromagnetic Principles Of Gpr Surveyingmentioning

confidence: 99%

“…Recently, advances in GPR technology such as real-time sampling and pulse compression technology have been shown to significantly improve the depths of penetration possible with radar in suitable geologies (Francke and Utsi, 2009). Commercial availability of the latest technologies will enable GPR to function in areas currently unsuitable such as clayey soils, improve penetration depth, resolution and speed of surveying.…”

Section: Final Remarksmentioning

confidence: 99%

Imaging frozen glacio-fluvial bedrock valley infill using Ground Penetrating Radar

Afanasyev

2010

First International Conference on Frontiers in Shallow Subsurface Technology

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Faculty of Civil Engineering and Geosciences Department of Geotechnology Master of Science by Michael Afanasyev B.Sc. A Ground Penetrating Radar (GPR) survey was conducted in April of 2008, collecting 27 km of radar profiles in Sandflugtdalen, a permafrosted glacio-fluvial bedrock valley in West Greenland. Due to low electric permittivity of frozen soil, GPR has good depth penetration of permafrost, up to 80 m using low-frequency (50 MHz) antennae.Resolution of reflections from subsurface structures are improved by gain application and frequency filtering. Migration reconstructs the radar image to make it look more like the geological structure in the subsurface. Using the principles of radar stratigraphy, 6 types of radar facies are identified in the dataset -chaotic (shallow), parallel, subparallel, oblique, chaotic with reflection and chaotic (deep); the facies are interpreted respectively as non-geological artifacts, related to system problems, lacustrine deposits (both parallel and sub-parallel facies), delta foresets, glacial till and/or moraine deposits, and bedrock. Average bedrock depth in Sandflugtdalen is ∼ 50 meter. Bedrock barriers, overlaid by push moraines, divide Sandflugtdalen in 3 subbasins. Radar packages of delta foresets, till and lacustrine deposits in each subbasin are interpreted to be have been deposited in at least 3 individual moraine-dammed lakes, that existed in front of the glacier during glacial retreat, between 10.5 ka ago and ∼ 5 ka ago. A 3-D model of the bedrock surface is generated and based on the model the sediment volume in the mapped area is calculated as 0.37 km 3 . Modeling the bedrock and mapping the sedimentary architecture in a filled glacial valley generates a base-case for model validation of short-term climate changes and effects on glacier and sedimentary system. PrefaceDuring the past two years, I have followed the Joint Master's in Applied Geophysics, a two-year programme offered by the IDEA League partners -TU Delft, ETH Zurich and RWTH Aachen. I have attended courses, conducted experiments, written reports and passed exams with fellow students from 10 different countries. Together, we have partied, traveled, climbed mountains and have learned a lot not only about geophysics but also about each other. It has been a truly unique experience.The last part of the Joint Master's programme is dedicated to thesis project. This report is written as part of the graduation thesis work, that I have done at the

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Advances in long-range GPR systems and their applications to mineral exploration, geotechnical and static correction problems

Cited by 30 publications

References 0 publications

Orbiter-to-orbiter tomography: a potential approach for small solar system bodies

Orbiter-to-orbiter tomography: a potential approach for small solar system bodies

DISCUS – The Deep Interior Scanning CubeSat mission to a rubble pile near-Earth asteroid

Imaging frozen glacio-fluvial bedrock valley infill using Ground Penetrating Radar

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