The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Tapan Mukerji - One of the best experts on this subject based on the ideXlab platform.
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fast 3d ultra shallow seismic reflection imaging using portable geophone mount
Geophysical Research Letters, 2001Co-Authors: Ran Bachrach, Tapan MukerjiAbstract:We present the results of three different seismic experiments designed to develop and evaluate the use of 3D Ultra Shallow Seismic Reflection for high-resolution near-surface imaging. A feasibility study and the first implementation of a 2D portable geophone mount for fast and cost-effective ultra-shallow 3D seismic data acquisition are discussed. The portable geophone mount is made out of an anelastic base with a frame and an array of 72 Geophones spaced with an interval of 0.25m both in the inline and crossline direction. The array enables acquisition of very high-resolution 3D data cubes with bin size of 12.5 × 12.5cm and wavelets of 350Hz. The time for re-planting the 72-channels portable geophone mount is about 5min in the field. Thus, we show that high-resolution near-surface 3D images can be obtained fast and in a cost-effective manner. This has the potential of providing effective solutions for many geotechnical and geoenvironmental applications.
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fast 3d ultra shallow seismic reflection imaging using portable geophone mount
14th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, 2001Co-Authors: Ran Bachrach, Tapan MukerjiAbstract:In this paper we present the results of a suite of seismic experiments designed to develop and evaluate the use of 3D Ultra Shallow Seismic Reflection System for high resolution near surface imaging. A feasibility study and the first implementation of 2D portable geophone mounted array for fast and cost effective ultra shallow 3D seismic data acquisition are discussed. The new portable geophone mount is made out of anelastic base with a frame and 72 Geophones spaced in an array. Geophone interval of 0.25m both in the inline and crossline direction enables acquisition of very highresolution 3D data cubes with bin size of 12.5x12.5cm and wavelets of 350Hz. The time of re-planting the 72 channels portable geophone mount is about 5min in the field. We also developed a data acquisition quality control and real time imaging that can be preformed on a portable computer in the field and produce 3D images in real time. Thus, we show that high-resolution near-surface 3D seismic images can be obtained rapidly, and in a cost-effective manner. This has the potential of providing effective solutions for many geotechnical and geoenvironmental applications.
Ran Bachrach - One of the best experts on this subject based on the ideXlab platform.
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fast 3d ultra shallow seismic reflection imaging using portable geophone mount
Geophysical Research Letters, 2001Co-Authors: Ran Bachrach, Tapan MukerjiAbstract:We present the results of three different seismic experiments designed to develop and evaluate the use of 3D Ultra Shallow Seismic Reflection for high-resolution near-surface imaging. A feasibility study and the first implementation of a 2D portable geophone mount for fast and cost-effective ultra-shallow 3D seismic data acquisition are discussed. The portable geophone mount is made out of an anelastic base with a frame and an array of 72 Geophones spaced with an interval of 0.25m both in the inline and crossline direction. The array enables acquisition of very high-resolution 3D data cubes with bin size of 12.5 × 12.5cm and wavelets of 350Hz. The time for re-planting the 72-channels portable geophone mount is about 5min in the field. Thus, we show that high-resolution near-surface 3D images can be obtained fast and in a cost-effective manner. This has the potential of providing effective solutions for many geotechnical and geoenvironmental applications.
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fast 3d ultra shallow seismic reflection imaging using portable geophone mount
14th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, 2001Co-Authors: Ran Bachrach, Tapan MukerjiAbstract:In this paper we present the results of a suite of seismic experiments designed to develop and evaluate the use of 3D Ultra Shallow Seismic Reflection System for high resolution near surface imaging. A feasibility study and the first implementation of 2D portable geophone mounted array for fast and cost effective ultra shallow 3D seismic data acquisition are discussed. The new portable geophone mount is made out of anelastic base with a frame and 72 Geophones spaced in an array. Geophone interval of 0.25m both in the inline and crossline direction enables acquisition of very highresolution 3D data cubes with bin size of 12.5x12.5cm and wavelets of 350Hz. The time of re-planting the 72 channels portable geophone mount is about 5min in the field. We also developed a data acquisition quality control and real time imaging that can be preformed on a portable computer in the field and produce 3D images in real time. Thus, we show that high-resolution near-surface 3D seismic images can be obtained rapidly, and in a cost-effective manner. This has the potential of providing effective solutions for many geotechnical and geoenvironmental applications.
M. Ali Ak - One of the best experts on this subject based on the ideXlab platform.
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AN ANALYTICAL RAYPATH APPROACH TO THE REFRACTION WAVEFRONT METHOD1
Geophysical Prospecting, 1990Co-Authors: M. Ali AkAbstract:Seismic refraction surveying is still an important tool for determining the geometries and elastic wave propagation velocities of near-surface layers. Many analytical and graphical methods have been developed over the years for refraction interpretation, and these can be classified into two basic groups. The first group visualizes critically refracted rays converging on a common surface position, while the second group, which includes the wavefront methods, makes use of the critical rays emerging from a common point on the refractor. The method described in this paper is an analytical approach to the wavefront methods. The reverse refracted ray received by a geophone is intersected by the forward refracted rays received by subsequent Geophones and a common critical refraction point on the refractor is estimated after a series of comparisons. This process is repeated for each geophone to yield the geometry and the velocity of the refractor. Several interpolations are performed to achieve a better accuracy. Palmer's models are used to test the efficiency of the algorithm. The results are presented together with those of other methods applied to the same models.
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An analytical raypath approach to the refraction wavefront method
1990Co-Authors: M. Ali AkAbstract:An algorithm for refraction interpretation is described. The reverse refracted ray received by a geophone is intersected by the forward refracted rays received by subsequent Geophones and a common critical refraction point on the refractor is estimated after a series of comparisons. This process is repeated for each geophone to yield the geometry and the velocity of the refractor. Several interpolations are performed to achieve a better accuracy. The algorithm is tested using Palmer's models
Aaron T Becker - One of the best experts on this subject based on the ideXlab platform.
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seismic surveying with drone mounted Geophones
Conference on Automation Science and Engineering, 2016Co-Authors: Srikanth K V Sudarshan, Li Huang, Robert R Stewart, Aaron T BeckerAbstract:Seismic imaging is the primary technique for subsurface exploration. Traditional seismic imaging techniques rely heavily on manual labor to plant sensors, lay miles of cabling, and then recover the sensors. Often sites of resource or rescue interest may be difficult or hazardous to access. Thus, there is a substantial need for unmanned sensors that can be deployed by air and potentially in large numbers. This paper presents working prototypes of autonomous drones equipped with Geophones (vibration sensors) that can fly to a site, land, listen for echoes and vibrations, store the information on-board, and subsequently return to home base. The design uses four geophone sensors (with spikes) in place of the landing gear. This provides a stable landing attitude, redundancy in sensing, and ensures the Geophones are oriented perpendicular to the ground. The paper describes hardware experiments demonstrating the efficacy of this technique and a comparison with traditional manual techniques. The performance of the seismic drone was comparable to a well planted geophone, proving the drone mount system is a feasible alternative to traditional seismic sensors.
Robert R Stewart - One of the best experts on this subject based on the ideXlab platform.
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seismic surveying with drone mounted Geophones
Conference on Automation Science and Engineering, 2016Co-Authors: Srikanth K V Sudarshan, Li Huang, Robert R Stewart, Aaron T BeckerAbstract:Seismic imaging is the primary technique for subsurface exploration. Traditional seismic imaging techniques rely heavily on manual labor to plant sensors, lay miles of cabling, and then recover the sensors. Often sites of resource or rescue interest may be difficult or hazardous to access. Thus, there is a substantial need for unmanned sensors that can be deployed by air and potentially in large numbers. This paper presents working prototypes of autonomous drones equipped with Geophones (vibration sensors) that can fly to a site, land, listen for echoes and vibrations, store the information on-board, and subsequently return to home base. The design uses four geophone sensors (with spikes) in place of the landing gear. This provides a stable landing attitude, redundancy in sensing, and ensures the Geophones are oriented perpendicular to the ground. The paper describes hardware experiments demonstrating the efficacy of this technique and a comparison with traditional manual techniques. The performance of the seismic drone was comparable to a well planted geophone, proving the drone mount system is a feasible alternative to traditional seismic sensors.
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comparison of mems accelerometers and Geophones at spring coulee alberta
2008Co-Authors: Michael S Hons, Robert R StewartAbstract:Geophone and MEMS accelerometer data from a field experiment at Spring Coulee, Alberta are compared in the acceleration domain. At receiver stations where coupling and noise are not a problem, measurements from both sensor types are found to be very similar. Several different analyses of signal-to-noise ratio indicate a small advantage for Geophones at low and medium frequencies, at later arrival times and longer offsets. Accelerometers appear to have a small advantage at higher frequencies, shorter arrival times and shorter offsets.
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field data comparison 3c 2d data acquisition with Geophones and accelerometers
Seg Technical Program Expanded Abstracts, 2008Co-Authors: Glenn Hauer, Don C. Lawton, Malcolm B. Bertram, Robert R Stewart, Michael S HonsAbstract:We report on a field comparison of different seismic motion sensors. The CREWES Project at the University of Calgary acquired a 3C-2D seismic line in the Spring Coulee area of Southern Alberta in January 2008. This was a unique opportunity to compare two types of multicomponent sensors with acquisition occurring at the same time and with the same receiver parameters. This 6.52 km 2D acquisition was laid out with a digital MEMS accelerometer: the DSU3-428 and the accompanying Sercel 428XL recording system; as well as an analog 3C geophone: the SM-7 high resolution geophone element placed in a modified PE-6/S nail type case co-developed by Sensor Nederland (A Division of ION Geophysical) and ARAM Systems with the accompanying ARAM Aries MC recording system. There have been limited acquisition comparison tests performed and/or published with MEMS accelerometers and analog Geophones in the past; the purpose of this study is to compare data acquired with single-point 3C receivers laid out side-side in a commercial recording environment.
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implications from transfer functions when comparing seismic data from mems accelerometers and Geophones
2007Co-Authors: Michael S Hons, Robert R StewartAbstract:Summary Digital sensors based on micro electro mechanical systems (MEMS) accelerometers are one of the newest technologies being used in seismic acquisition. As such, there remains some confusion surrounding the similarities and differences relative to the coil-over-magnet geophone. By modeling the transfer functions of these devices and convolving displacement domain wavelets of varying frequency content with them, it will be demonstrated that raw electrical signals output by the sensor elements are expected to be similar in appearance. Also, the dominant frequency of the wavelet relative to the geophone’s resonant frequency determines whether the MEMS accelerometer result is an apparent phase lead or phase lag relative to the geophone result.
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ground motion through Geophones and mems accelerometers sensor comparison in theory modeling and field data
Seg Technical Program Expanded Abstracts, 2007Co-Authors: Michael S Hons, Don C. Lawton, Robert R Stewart, Malcolm B. BertramAbstract:Summary Digital sensors based on micro electro mechanical systems (MEMS) accelerometers are one of the newest technologies being used in seismic acquisition. As such, some confusion remains surrounding similarities and differences relative to the coil-over-magnet geophone. An understanding of the functioning of these sensors and how to compare them can be facilitated by deriving transfer functions, which relate the data acquired through each sensor to actual ground motion. An equation is then derived to calculate acceleration comparable to unprocessed MEMS data from unprocessed geophone data. The inverse of this equation may be used to calculate geophone data from MEMS data. The effects of sensors on zero and minimum phase wavelets are modeled, demonstrating that the raw output from the sensors should be similar. The minimum phase wavelets are convolved with a random reflectivity series to test deconvolution of impulsive source data. Deconvolution produces geophone and MEMS processed traces that appear similar, and constant phase rotation of MEMS data after deconvolution cannot correct all remaining differences. The geophone-to-MEMS transfer equation will exactly transfer between sensors only in the absence of instrument noise. Comparisons between MEMS and Geophones recording the same shots, and ground motion domains calculated from those records, show that the data is very similar in frequency content when the same domain is considered, and MEMS records will not necessarily have a larger magnitude contribution from low frequencies than
