Results 91 to 100 of about 145 (123)
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Evaluation of an array type directional borehole radar system
Proceedings. 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005. IGARSS '05., 2005An array type directional borehole radar system employing passive sensors, optical electric field sensors was developed. The system uses a dipole antenna for transmission and four optical electric field sensors for reception. Four sensors are evenly arranged in the circumferential direction to constitute an antenna array.
Takuya Takayama, Motoyuki Sato
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A High-Resolution, Short-Range, Directional Borehole Radar
14th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, 2001The U.S. Geological Survey (USGS) has recently developed a prototype directional borehole radar system designed to complement a commercial system that the USGS has used for several years for fracture mapping in crystalline rock. The new prototype is designed for higher resolution, shorter range operation.
David L. Wright +3 more
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A directional monostatic borehole radar system
2013 7th International Workshop on Advanced Ground Penetrating Radar, 2013A directional, monostatic borehole radar system was developed to overcome some disadvantages of the existing bistatic system. The challenges of combining transmitter and receiver in a single module are apparent, since one wants both high transmitting power and high receiver sensitivity.
Matthias Boger, Albrecht Glasmachers
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A directional borehole radar: numerical and experimental verification
IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229), 2002We present the simulation and design of an antenna system for a borehole radar. To obtain a directional radiation pattern the transmitting dipole is shielded with a reflector. The generated transient wavefield, with a centre frequency of 100 MHz, is reflected in the desired direction by a perfectly conducting cylindrically curved plate.
K.W.A. van Dongen +2 more
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Dnapl Detection Sensitivity Of A High-Resolution Directional Borehole Radar
16th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, 2003The U.S. Geological Survey has developed a directional borehole radar system (DBOR) for high-resolution imaging close to borehole wells. We have conducted physical and numerical modeling to assess the ability of this radar to detect and map the location of dense non-aqueous phase liquids (DNAPLs) near a borehole.
Craig W. Moulton, David L. Wright
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Experiments in skarn with a polarization-sensitive directional borehole radar
2016 16th International Conference on Ground Penetrating Radar (GPR), 2016This paper describes experimental results carried out in skarn deposits with a polarization-sensitive directional borehole radar. This radar employs a dipole array and loop antenna in a borehole (DALAB), which was proposed in a previous study. This radar system was applied to polarimetric radar measurement of a fault and sphalerite veins in skarn.
S. Ebihara +4 more
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3-D Imaging of a Planar Interface Close to a Borehole with an Array-Type Directional Borehole Radar
IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019We propose an algorithm for creating a 3-D image of a planar interface with an array-type directional borehole radar. In this paper, we focus on the situation when the radar probe is close to the planar interface. In such circumstances, the reflected wave from the planar interface may be incident on the receiving array antenna at very steep elevation ...
Satoshi Ebihara +2 more
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Borehole Directional Radar System for Subsurface Scanning
Proceedings of SPE Annual Technical Conference and Exhibition, 1989Abstract This paper summarizes the progress in the development of the Borehole Directional Radar (BDR). The theory for using radar for geological mapping is shown, and the design and characteristics of the antenna are discussed. The results of field tests in rock formations under both dry and wet conditions are presented.
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Borehole directional radar system for geological mapping4
Journal of Atmospheric and Terrestrial Physics, 1989Abstract This paper summarizes the progress in the development of the Borehole Directional Radar (BDR), which is a high-powered, high-resolution pulsed system that will be used for mapping geological layers or fractures away from a wellbore. The key to the tool's potential is its ability to accurately measure distance and direction of a lithologie ...
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Analysis of a direct wave in directional borehole radar with a circular dipole array antenna
2012 14th International Conference on Ground Penetrating Radar (GPR), 2012In this paper, we discuss influence of radar sonde on a direct wave in singlehole directional borehole radar using a circular dipole array. The numerical simulation shows that the guided wave, HE 11 mode, is excited at the higher frequencies than 200 MHz only when the radar sonde is eccentered in a water-filled borehole.
S. Ebihara, K. Onoda
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