The Vibroseis system: A high‐frequency tool

Geophysics ◽  
1981 ◽  
Vol 46 (12) ◽  
pp. 1657-1666 ◽  
Author(s):  
Wm. L. Chapman ◽  
G. L. Brown ◽  
D. W. Fair
Keyword(s):  
Data Processing ◽  
High Frequency ◽  
Dynamic Range ◽  
Spectral Response ◽  
Seismic Signal ◽  
Acquisition System ◽  
System Response ◽  
System A ◽  
Seismic Acquisition ◽  
Correct Application

Exploration methods are extended to their limits as we continue the search for energy resources. Successful application of high‐frequency seismic method requires evaluating each element in the seismic acquisition system and ensuring that each part of the system contributes to the success of the method. This extends from seismic signal generation through data processing where good equipment performance and correct parameter selections are required. The Vibroseis® system depends upon the ability of vibrators to generate synchronous, repeatable sweeps over the frequency range of interest. To support our high‐frequency seismic efforts, Conoco, Inc., has developed and built a new high‐frequency vibrator. This paper includes some of the consideration used in building the vibrator, along with typical baseplate responses showing excellent drive levels to the design goal of 200 Hz. With an excellent source available, correct application is essential to assure retention of high‐frequency data. Recording offsets, array lengths, and array sampling must be selected for the sweep frequencies used. Also, approximate matching of the data acquisition system response to the spectral response of the earth reduces the dynamic range requirements for recording systems and subsequent data processing. Data are included showing the successful application of high‐frequency techniques to stratigraphic exploration problems.

scholarly journals High-frequency rectifiers based on type-II Dirac fermions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Libo Zhang ◽  
Zhiqingzi Chen ◽  
Kaixuan Zhang ◽  
Lin Wang ◽  
Huang Xu ◽  
...  
Keyword(s):  
High Frequency ◽  
Dynamic Range ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Anisotropy Ratio ◽  
Dirac Fermions ◽  
Topological States ◽  
Topological Semimetals ◽  
Polarized Surface ◽  
Symmetry Protected

AbstractThe advent of topological semimetals enables the exploitation of symmetry-protected topological phenomena and quantized transport. Here, we present homogeneous rectifiers, converting high-frequency electromagnetic energy into direct current, based on low-energy Dirac fermions of topological semimetal-NiTe2, with state-of-the-art efficiency already in the first implementation. Explicitly, these devices display room-temperature photosensitivity as high as 251 mA W−1 at 0.3 THz in an unbiased mode, with a photocurrent anisotropy ratio of 22, originating from the interplay between the spin-polarized surface and bulk states. Device performances in terms of broadband operation, high dynamic range, as well as their high sensitivity, validate the immense potential and unique advantages associated to the control of nonequilibrium gapless topological states via built-in electric field, electromagnetic polarization and symmetry breaking in topological semimetals. These findings pave the way for the exploitation of topological phase of matter for high-frequency operations in polarization-sensitive sensing, communications and imaging.

Design and Implement of Data Acquisition System Based on Reconfigurable Computing

2012 ◽  
Vol 546-547 ◽  
pp. 1393-1397
Author(s):  
Zhi Wen Xiong ◽  
Chen Guang Xu ◽  
Hong Zeng
Keyword(s):  
Data Processing ◽  
Data Acquisition ◽  
Reconfigurable Computing ◽  
Rapid Development ◽  
Physical Property ◽  
Data Acquisition System ◽  
Digital System ◽  
Working Environment ◽  
Acquisition System ◽  
Computing Technology

Data acquisition begins with the physical phenomenon or physical property to be measured. Examples of this include temperature, gas pressure, and light intensity, and force, fluid flow, regardless of the type of physical property to be measured. Physical property converted into digital, and then by the computer for storage, processing, display or printing process, the corresponding system is called data acquisition system. With the rapid development of computer technology, data acquisition systems quickly gained popularity. A variety of products based on digital technology have been created. Digital System spread quickly; it’s mainly the following two advantages: the first is the digital processing flexible and convenient; the second is a digital system is very reliable. The main idea of Reconfigurable computing technology [1] is using the FPGA [2][3] allows the system has a dynamically configurable capacity, suitable for harsh environment applications, improve the speed of data processing. By the use of dynamic reconfigurable FPGA devices can be realized on the hardware logic function modification, application of reconfigurable computing technology can improve the speed of data processing. Data acquisition system is widely applied in many fields, and often used the abominable working environment place. The reconfigurable computing technology, can greatly improve the data acquisition system reliability and safety. The paper introduces a kind of multi-channel data acquisition system based on USB bus and FPGA, the factors affecting the performance of system are discussed, and describes how to use reconfigurable computing technology to improve the efficiency of data acquisition system while reduce energy consumption. The system in this paper uses AD's AD9220, ALTERA's EP1C6-8 and IDT's IDT70V24, Cypress’s CY7C68013.

Clock signal requirement for high-frequency, high dynamic range acquisition systems

2005 ◽  
Vol 76 (11) ◽  
pp. 115103 ◽  
Author(s):  
Ivo Viščor ◽  
Josef Halámek ◽  
Marco Villa
Keyword(s):  
High Frequency ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Clock Signal ◽  
High Dynamic

Mechanism of Heme Uptake by Heme Acquisition System A

2011 ◽  
Vol 40 (4) ◽  
pp. 362-363 ◽  
Author(s):  
Shin-ichi Ozaki ◽  
Akira Nakahara ◽  
Takehiro Sato
Keyword(s):  
Acquisition System ◽  
Heme Uptake ◽  
System A ◽  
Heme Acquisition

scholarly journals Data Transmission Technology of Line Acquisition Unit in Seismic Acquisition System

2011 ◽  
Vol 15 ◽  
pp. 2388-2392 ◽  
Author(s):  
Yinge Kong ◽  
Ming Deng ◽  
Jian Guo ◽  
Weibing Luo
Keyword(s):  
Data Transmission ◽  
Acquisition System ◽  
Seismic Acquisition

Blended acquisition with dispersed source arrays

Geophysics ◽  
2012 ◽  
Vol 77 (4) ◽  
pp. A19-A23 ◽  
Author(s):  
A. J. Berkhout
Keyword(s):  
High Frequency ◽  
Spatial Sampling ◽  
Acquisition Process ◽  
Air Gun ◽  
Seismic Acquisition ◽  
Sampling Intervals ◽  
Source Array

Blended source arrays are historically configured with equal source units, such as broadband vibrators (land) and broadband air-gun arrays (marine). I refer to this concept as homogeneous blending. I have proposed to extend the blending concept to inhomogeneous blending, meaning that a blended source array consists of different source units. More specifically, I proposed to replace in blended acquisition the traditional broadband sources by narrowband versions — imagine coded single air guns with different volumes or coded single narrowband vibrators with different central frequencies — together representing a dispersed source array (DSA). Similar to what we see in today’s audio systems, the DSA concept allows the design of dedicated narrowband source elements that do not suffer from the low versus high frequency compromise. In addition, the DSA concept opens the possibility to use source depths and spatial sampling intervals that are optimum for the low-, mid-, and high-frequency sources (multiscale shooting grids). DSAs are considered to be an important step in robotizing the seismic acquisition process.

scholarly journals The new NCPSS BL19U2 beamline at the SSRF for small-angle X-ray scattering from biological macromolecules in solution

2016 ◽  
Vol 49 (5) ◽  
pp. 1428-1432 ◽  
Author(s):  
Na Li ◽  
Xiuhong Li ◽  
Yuzhu Wang ◽  
Guangfeng Liu ◽  
Ping Zhou ◽  
...  
Keyword(s):  
Data Processing ◽  
Small Angle ◽  
Dynamic Range ◽  
Silicon Crystal ◽  
High Dynamic Range ◽  
Biological Macromolecules ◽  
Shanghai Synchrotron Radiation Facility ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

The beamline BL19U2 is located in the Shanghai Synchrotron Radiation Facility (SSRF) and is its first beamline dedicated to biological material small-angle X-ray scattering (BioSAXS). The electrons come from an undulator which can provide high brilliance for the BL19U2 end stations. A double flat silicon crystal (111) monochromator is used in BL19U2, with a tunable monochromatic photon energy ranging from 7 to 15 keV. To meet the rapidly growing demands of crystallographers, biochemists and structural biologists, the BioSAXS beamline allows manual and automatic sample loading/unloading. A Pilatus 1M detector (Dectris) is employed for data collection, characterized by a high dynamic range and a short readout time. The highly automated data processing pipeline SASFLOW was integrated into BL19U2, with help from the BioSAXS group of the European Molecular Biology Laboratory (EMBL, Hamburg), which provides a user-friendly interface for data processing. The BL19U2 beamline was officially opened to users in March 2015. To date, feedback from users has been positive and the number of experimental proposals at BL19U2 is increasing. A description of the new BioSAXS beamline and the setup characteristics is given, together with examples of data obtained.

scholarly journals RECONSTRUCTION OF INDOOR MODELS USING POINT CLOUDS GENERATED FROM SINGLE-LENS REFLEX CAMERAS AND DEPTH IMAGES

2015 ◽  
Vol XL-4/W5 ◽  
pp. 99-102
Author(s):  
F. Tsai ◽  
T.-S. Wu ◽  
I.-C. Lee ◽  
H. Chang ◽  
A. Y. S. Su
Keyword(s):  
Data Processing ◽  
Data Acquisition ◽  
Three Dimensional ◽  
Point Clouds ◽  
Data Acquisition System ◽  
Acquisition System ◽  
Indoor Environments ◽  
Single Lens ◽  
Processing Procedure ◽  
Data Processing Procedure

This paper presents a data acquisition system consisting of multiple RGB-D sensors and digital single-lens reflex (DSLR) cameras. A systematic data processing procedure for integrating these two kinds of devices to generate three-dimensional point clouds of indoor environments is also developed and described. In the developed system, DSLR cameras are used to bridge the Kinects and provide a more accurate ray intersection condition, which takes advantage of the higher resolution and image quality of the DSLR cameras. Structure from Motion (SFM) reconstruction is used to link and merge multiple Kinect point clouds and dense point clouds (from DSLR color images) to generate initial integrated point clouds. Then, bundle adjustment is used to resolve the exterior orientation (EO) of all images. Those exterior orientations are used as the initial values to combine these point clouds at each frame into the same coordinate system using Helmert (seven-parameter) transformation. Experimental results demonstrate that the design of the data acquisition system and the data processing procedure can generate dense and fully colored point clouds of indoor environments successfully even in featureless areas. The accuracy of the generated point clouds were evaluated by comparing the widths and heights of identified objects as well as coordinates of pre-set independent check points against in situ measurements. Based on the generated point clouds, complete and accurate three-dimensional models of indoor environments can be constructed effectively.

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