检索结果-内蒙古大学图书馆

Reservoir modeling using scale-dependent data

SPE JOURNAL 2001年第2期6卷 157-170页

作者： Panda, MN Mosher, C Chopra, AK Arco E&P Technol Plano TX USA

A reservoir description incorporating the precision and scale of all available data (geological, petrophysical seismic, tracer, and well-test data) is critical for reservoir modeling. The heterogeneous variables sampled by these data are composed of several superimposed functions, each characterized by a unique spatial and temporal scale or support. For example, core, well-log, well-test, and seismic data have supports ranging from inches to thousands of feet. Current geostatistical methods map lithofacies, porosity, and permeability on a network of grid nodes called the geologic modeling cells. Pseudopoint properties that assimilate information from all available data are modeled onto model cells using one of several available conditional-simulation techniques. Some methods attempt to combine data with varying support, and data with multiple-scale support, through simple correlations. For example, one approach to incorporate geophysical data is to use a direct transform of the seismic signal to rock properties through a linear regression or crossplot. Reservoir models built using such linear correlations tend to be case-specific with little generality. This paper presents a method for identifying the impact of multiscale data (data that measure average property over multiple-flow units) on reservoir modeling. It examines the information about the reservoir system each data type carries, for example, what fraction of core scale variability is captured by well-log data. We also present a consistent method for integrating multiscale data. Through a series of numerical simulations, we show the impact of reservoir-property heterogeneity on the fluid-flow performance.

关键词： heterogeneity variance seismic data upstream oil & gas resolution log data effective permeability geologic modeling correlation range modeling & simulation Flow in porous media Formation evaluation & Management Geologic modeling Improved and Enhanced Recovery Information Management and systems Reservoir Characterization Reservoir Fluid Dynamics Reservoir simulation Scaling methods Seismic processing and interpretation

来源：评论

学校读者我要写书评

暂无评论

The Northrop Grumman avionics simulation (AVSIM)

The Northrop Grumman avionics simulation (AVSIM)

引用

AIAA modeling and simulation Technologies Conference and Exhibit 2001

作者： Worsham, Richard H. Systems Engineering and Simulation Systems Development and Technology Division Electronic Sensors and Systems Sector Northrop Grumman Corporation Baltimore MD United States

ISBN: (纸本)9781563479458

The Northrop Grumman Avionics simulation (AVSIM) is one of a set of simulations focused on fighter class radars. It is designed to support a variety of analysis and development activities, spanning requirements analysis, radar software development, performance evaluation, and pilot interfaces. This paper describes AVSIM and the simulation architecture that surrounds it. The model provides high fidelity representations of both Air-to-Air and Air-to-Ground radar modes, encompassing detection capability, measurement errors, tracking performance, and timelines. Analytical models are used to represent high data rate signal processing functions, while operational software is used for less intensive data processing such as radar control and tracking activities. AVSIM can be driven by models such as the Joint Integrated Mission Model (JIMM), or by tightly controlled scenarios from its own Scenario Generator. It can be run in real time as part of a cockpit simulator, or in Monte Carlo mode for detailed performance analysis. Extensive post processing capabilities provide insight into radar detection, measurement errors, tracking, and timeline performance. Scan patterns are also visualized, via playback capabilities. AVSIM represents a substantial advance in the state of the art for high fidelity multi-use avionics simulations. © 2001 by the Northrop Grumman Corporation. Published by the American Institute of Aeronautics and Astronautics, Inc.

关键词： Software design

来源：评论

学校读者我要写书评

暂无评论

Aliasing effects in thermal images of four-bar patterns below and above the Nyquist limit

Aliasing effects in thermal images of four-bar patterns belo...

引用

35th Asilomar Conference on signals, systems and Computers

作者： Celik, M Kenter, Y Cooper, A Pieper, R USN Postgrad Sch Monterey CA 93943 USA

ISBN: (纸本)078037147X

A new virtual thermal image-processing model is introduced in this paper. This visualization program is based on earlier modeling work focused on predicting the minimum resolvable temperature (MRTD), which is a standard performance measure for forward looking infrared radar (FLIR) imaging systems. Relevant filtering, noise and sampling processes are included in the visualization model. In this paper it will be demonstrated and explained that aliasing effects in thermal images of four-bar patterns cannot in general he adequately modeled as noise. In particular, the simulation experiments demonstrate that aliasing can have a noticeable visual enhancing effect at spatial bar frequencies less than the Nyquist limit.

关键词： image processing

来源：评论

学校读者我要写书评

暂无评论

Impact of large sidelobe discretes in SAR image formation

Impact of large sidelobe discretes in SAR image formation

引用

Sensors, systems, and Next-Generation Satellites V Conference

作者： Maher, JE Lynch, ED Schneible, RA Wicks, MC Zhang, Y Air Force Research Lab. (United States) Research Associates for Defense Conversion Inc. (United States)

ISBN: (纸本)0819442658

In this paper, the U.S. Air Force's Research Laboratory Space-Time Adaptive processing (RLSTAP) tool is used to demonstrate the impact of large sidelobe discretes on modem Synthetic Aperture Radar (SAR) signal and image processing. Sidelobe discretes may mask or even completely obscure weak target returns of interest in the immediate vicinity of these strong returns. Adaptive processing offers the potential to mitigate the effects of strong sidelobe discretes on image formation. In this paper, we characterize the severity of the problems caused by these discretes. RLSTAP can simulate high-fidelity airborne, spaceborne, or ground based multi-channel radar data in jamming and clutter environments, develop and evaluate new signal and image processing algorithms, and assess the performance of advanced radar systems. RLSTAP is a time domain simulation, updating object positions for every radar pulse and allowing modeling of realistic effects such as returns "walking" across range bins and Doppler filters. The site-specific clutter model uses terrain elevation and cover data to derive the line-of-site visibility, grazing angle, and clutter type for each range-angle cell. Spatial and temporal clutter statistics are applied to each cell and the signal strength at the receiver is calculated as a function of the backscatter coefficient, range, atmospheric attenuation, antenna gain, and system gains/losses. The scene generation capability in RLSTAP is unique in that it exploits Defense Terrain Elevation Data (DTED) and Land Use Land Cover Data (LULC) to create realistic clutter scenes (data cubes) for any given geographic location. As such, the application of adaptive multi-channel/multi-pulse processing to radar data that is characteristic of the area being imaged is now possible. Furthermore, the selection of waveform parameters, signal and image processing techniques, and associated radar parameters may be improved upon.

关键词： synthetic aperture radar modeling and simulation large sidelobe discretes

来源：评论

学校读者我要写书评

暂无评论

Spotlight synthetic aperture radar (SAR) requirements evaluation using phenomenology-based image quality metrics

Spotlight synthetic aperture radar (SAR) requirements evalua...

引用

Conference on Radar Sensor Technology VI

作者： Clinard, M Miettinen, K Zavattero, P Eastman Kodak Co Rochester NY 14624 USA

ISBN: (纸本)0819440698

Next generation reconnaissance and Automatic Target Detection/Recognition (ATD/R) performance goals will impose new image quality requirements on integrated SAR hardware and software systems. signal processing techniques using demonstrated non-parametric autofocus methods such as the Phase Gradient Autofocus (PGA) algorithm and developments in robust super-resolution signal processing offer the opportunity for reducing overall system cost through utilization of less costly hardware options in integrated system design. Traditional requirements on image quality from integrated hardware-software SAR systems have used image quality metrics based on the characteristics of the overall system impulse response function. An additional class of image quality metrics is available based on the performance of the ATD/R algorithms that are to utilize the imagery. The performance of a given SAR system by these measures is expected to be context-sensitive and dependant on both target and clutter characteristics in a manner not necessarily readily characterizable solely in terms of system impulse response function measures of image quality. A simulation illustration of these issues is presented for a test case in which a range of SAR sensor hardware options are processed through a representative texture metric mechanization. Potential performance dependencies on target and clutter characteristics are reviewed and the efficacy of supplementing impulse response function image quality metrics with additional appropriate predictors of ATD/R performance is reviewed.

关键词： SAR image quality metrics Automatic Target Detection Automatic Target Recognition

来源：评论

学校读者我要写书评

暂无评论

Advances in the universal programmable interface (UPI) for hardware-in-the-loop (HWIL) sensor stimulation

Advances in the universal programmable interface (UPI) for h...

引用

Conference on Technologies for Synthetic Environments - Hardware-in-the-Loop Testing VI

作者： Weppner, MB McKee, DC Schlossman, PG Robinson, KJ Nuwer, ME Smith, LC Howe, DB Lagowski, HA Amherst Syst Inc Buffalo NY 14221 USA

ISBN: (纸本)0819440612

Amherst systems has developed a Universal Programmable Interface (UPI) for real-time modeling of sensor effects and other image processing functions. To properly test infrared sensors, the UPI must simulate by-passed sensor components, simulate optical blurring and distortion, simulate detector and sensor electronics performance, correct for projector optics, correct for projector non-uniformity, perform latency compensation, reformat image data and synchronize with the sensor. The UPI is designed to perform these functions as a re-configurable interface for hardware-in-the-loop (HWIL) testing of infrared and electro-optical (IR/EO) sensor systems. The UPI uses a combination of large-scale Field Programmable Gate Array (FPGA) and PowerPC multi-processor technologies. The UPI supports the interface between the Amherst systems Real-Time IR/EO Scene simulation (RISS) Scene Generation System (SGS) and the Unit Under Test (UUT) sensor. The UPI supports both direct injection of image date into the electronics of the sensor or optical projection into the aperture of the sensor. A sensor-specific, Sensor Injection Module (SIM) was developed for the F-22 Missile Launch Detector (MLD), as well as other sensors, for direct injection of the infrared imagery. This paper discusses recent advances in the development and applications of the UPI. Development milestones and current performance benchmarks will be presented.

关键词： hardware-in-the-loop sensor stimulation signal injection electro-optic infrared sensor effects modeling F22 MLD

来源：评论

学校读者我要写书评

暂无评论

Efficient evaluation of reverberant sound fields

Efficient evaluation of reverberant sound fields

引用

IEEE Workshop on Applications of signal processing to Audio and Acoustics

作者： R. Duraiswami N.A. Gumerov D.N. Zotkin L.S. Davis Perceptual Interfaces and Reality Laboratory Institute of Advanced Computer Studies University of Maryland College Park MD USA

An image method due to Allen and Berkley (1979) is often used to simulate the effect of reverberation in rooms. This method is relatively expensive computationally. We present a fast method for conducting such simulations using multipole expansions. For M real and image sources and N evaluation points, while the image method requires O(MN) operations, our method achieves the calculations in O(M + N) operations, resulting in a substantial speedup. Applications of our technique are also expected in simulation of virtual audio.

关键词： Computational modeling performance evaluation Impedance Microphone arrays Nails Laboratories Computer interfaces Educational institutions Computer simulation Reverberation

来源：评论

学校读者我要写书评

暂无评论

Adaptive resolution of mainlobe and sidelobe detections using model order determination

Adaptive resolution of mainlobe and sidelobe detections usin...

引用

International Conference on Acoustics, Speech, and signal processing (ICASSP)

作者： A.G. Jaffer J.C. Chen T.W. Miller Raytheon Electronic Systems Los Angeles California Raytheon Electronics Systems Los Angeles CA USA

This paper presents the development and performance evaluation of a methodology for distinguishing between mainlobe and sidelobe detections that arise in adaptive radar systems operating in adverse environments. Various adaptive detection test statistics such as the adaptive matched filter (AMF), the generalized likelihood ratio test (GLRT) and adaptive coherence estimate (ACE), and combinations of these, have been previously analyzed with respect to their sidelobe rejection capabilities. In contrast to these methods, which are based on detecting a single target with known direction and Doppler, the present method uses model order determination techniques applied to the AMF or GLRT data observed over the range of unknown angle and Doppler parameters. The determination of model order, i.e., the number of signals present in the data, is made by using least-squares model fit error residuals and applying the Akaike information criterion. Comprehensive computer simulation results are presented which demonstrate substantial improvement in sidelobe rejection performance compared to previous methods.

关键词： Testing Radar detection Brain modeling Computer simulation Covariance matrix Statistical analysis Matched filters Maximum likelihood detection Array signal processing Interference

来源：评论

学校读者我要写书评

暂无评论

Activity detection in unknown noise environment

Activity detection in unknown noise environment

引用

International Conference on Acoustics, Speech, and signal processing (ICASSP)

作者： E. Fishler H. Messer Department of Electrical Engineering Systems Tel-Aviv University Tel-Aviv Israel

In many applications there exists an array of cells (or bins), each containing either an activity (signal) plus noise, or noise only. A common problem is to identify the active bins, assuming that the noise level in the array is unknown. In this paper we present a novel approach for solving this problem. The approach is based on two steps. In the first, we estimate the noise level and in the second we perform a sequential test to decide, for each bin, whether it is active or not. We show that the proposed algorithm collapses to well known special cases. The performance of the proposed algorithm is analyzed analytically and is demonstrated via simulation results.

关键词： Working environment noise Noise measurement Noise level Wavelet transforms performance analysis Additive noise image denoising performance evaluation Sequential analysis Analytical models

来源：评论

学校读者我要写书评

暂无评论

A new diamond search algorithm for fast block-matching motion estimation (vol 9, pg 287, 2000)

引用

IEEE TRANSACTIONS ON image processing 2000年第3期9卷 525-525页

作者： Zhu, S Ma, KK V-BitsVideo Engineering Department Cisco Systems Inc. San Jose CA USA School of Electrical and Electronic Engineering Nanyang Technological University Singapore

Based on the study of motion vector distribution from several commonly used test image sequences, a new diamond search (DS) algorithm for fast block-matching motion estimation (BMME) is proposed in this paper. simulation results demonstrate that the proposed DS algorithm greatly outperforms the well-known three-step search (TSS) algorithm. Compared with the new three-step search (NTSS) algorithm, the DS algorithm achieves close performance but requires less computation by up to 22% on average. Experimental results also show that the DS algorithm is better than the four-step search (4SS) and block-based gradient descent search (BBGDS), in terms of mean-square error performance and required number of search points.

关键词： Motion estimation signal processing algorithms Video coding Video sequences Testing image sequences Video compression Computational modeling Transform coding Bandwidth

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：