The existence of aligned fractures in fluid-saturated rocks leads to obvious attenuation anisotropy and velocity anisotropy. Attenuation anisotropy analysis can be applied to estimate fracture density and scale, which...The existence of aligned fractures in fluid-saturated rocks leads to obvious attenuation anisotropy and velocity anisotropy. Attenuation anisotropy analysis can be applied to estimate fracture density and scale, which provide important information for reservoir identification. This paper derives P-wave attenuation anisotropy in the ATI media where the symmetry axis is in the arbitrary direction theoretically and modifies the spectral ratio method to measure attenuation anisotropy in the ATI media, thus avoiding a large measurement error when applied to wide azimuth or full azimuth data. Fracture dip and azimuth can be estimated through attenuation anisotropy analysis. For small-scale fractures, fracture scale and fracture density can be determined with enhanced convergence if velocity and attenuation information are both used. We also apply the modified spectralratio method to microseismic field data from an oilfield in East China and extract the fracture dip through attenuation anisotropy analysis. The result agrees with the microseismie monitoring.展开更多
灾后先进出行者信息系统(advanced traveler information system,ATIS)能及时为使用者提供交通信息,而非ATIS使用者只能根据自身历史经验调整路径。为了探究两类用户混合情景下的路网韧性,在韧性评价中引入了动态时间维度,构建了两类用...灾后先进出行者信息系统(advanced traveler information system,ATIS)能及时为使用者提供交通信息,而非ATIS使用者只能根据自身历史经验调整路径。为了探究两类用户混合情景下的路网韧性,在韧性评价中引入了动态时间维度,构建了两类用户混合日变动态配流模型,提出了基于历史流量的ATIS信息预测方法,并设计了模型求解算法。算例分析表明,所提出的ATIS信息预测方法与经典的ATIS信息预测方法相比,在研究时域内,前者支持下的平均路网韧性值相比后者提升了2.48%;针对路网韧性最优,最佳的ATIS市场占有率约为30%;当ATIS市场占有率为50%、75%、100%时,增大ATIS信息误差可提升路网韧性值,但当市场占有率为25%时,ATIS信息误差增大将导致路网韧性值降低。展开更多
A method of synchronous-high-derivative spectfluor for identification of crude oil and fuel oil pollution is studied. The best operation conditions for the 2nd and 4th deriv, are set. To differentiate oil-spill at riv...A method of synchronous-high-derivative spectfluor for identification of crude oil and fuel oil pollution is studied. The best operation conditions for the 2nd and 4th deriv, are set. To differentiate oil-spill at river and sea, this method is rapid and simple, and the spectra have high resolution power as 'fingerprint'.展开更多
Airborne Along-Track Interferometric Synthetic Aperture Radar (ATI-SAR) baseline error is a main error resource affecting the precision of velocity measurement of moving objects and therefore should be calibrated exte...Airborne Along-Track Interferometric Synthetic Aperture Radar (ATI-SAR) baseline error is a main error resource affecting the precision of velocity measurement of moving objects and therefore should be calibrated externally. The Jet Propulsion Laboratory (JPL) has proposed a calibration scheme for tasks of PacRim98 and PacRim2000 based on several static objects on the ground. In this paper, the influence of phase center uncertainty on baseline determination by using PacRim method proposed by JPL is analyzed. According to the analysis, the phase center uncertainty can cause a constant part of error to the result of baseline calibration. In order to deal with this problem, an improved calibration method on the basis of sensitivity equations and some ground moving targets, whose velocities are already known, is proposed in this paper. The simulation results show that our proposed calibration method has improved the accuracy of baseline calibration and has obviously prohibited the effect of antennas' phase center uncertainty.展开更多
基金supported by 973 Program of China(No.2013CB228602)National Science and Technology Major Project of China(No.2016ZX05004003-002)863 Program of China(No.2013AA064202)
文摘The existence of aligned fractures in fluid-saturated rocks leads to obvious attenuation anisotropy and velocity anisotropy. Attenuation anisotropy analysis can be applied to estimate fracture density and scale, which provide important information for reservoir identification. This paper derives P-wave attenuation anisotropy in the ATI media where the symmetry axis is in the arbitrary direction theoretically and modifies the spectral ratio method to measure attenuation anisotropy in the ATI media, thus avoiding a large measurement error when applied to wide azimuth or full azimuth data. Fracture dip and azimuth can be estimated through attenuation anisotropy analysis. For small-scale fractures, fracture scale and fracture density can be determined with enhanced convergence if velocity and attenuation information are both used. We also apply the modified spectralratio method to microseismic field data from an oilfield in East China and extract the fracture dip through attenuation anisotropy analysis. The result agrees with the microseismie monitoring.
文摘灾后先进出行者信息系统(advanced traveler information system,ATIS)能及时为使用者提供交通信息,而非ATIS使用者只能根据自身历史经验调整路径。为了探究两类用户混合情景下的路网韧性,在韧性评价中引入了动态时间维度,构建了两类用户混合日变动态配流模型,提出了基于历史流量的ATIS信息预测方法,并设计了模型求解算法。算例分析表明,所提出的ATIS信息预测方法与经典的ATIS信息预测方法相比,在研究时域内,前者支持下的平均路网韧性值相比后者提升了2.48%;针对路网韧性最优,最佳的ATIS市场占有率约为30%;当ATIS市场占有率为50%、75%、100%时,增大ATIS信息误差可提升路网韧性值,但当市场占有率为25%时,ATIS信息误差增大将导致路网韧性值降低。
文摘A method of synchronous-high-derivative spectfluor for identification of crude oil and fuel oil pollution is studied. The best operation conditions for the 2nd and 4th deriv, are set. To differentiate oil-spill at river and sea, this method is rapid and simple, and the spectra have high resolution power as 'fingerprint'.
基金Supported by the Key Project of National Natural Science Foundation of China (No. 60890070)
文摘Airborne Along-Track Interferometric Synthetic Aperture Radar (ATI-SAR) baseline error is a main error resource affecting the precision of velocity measurement of moving objects and therefore should be calibrated externally. The Jet Propulsion Laboratory (JPL) has proposed a calibration scheme for tasks of PacRim98 and PacRim2000 based on several static objects on the ground. In this paper, the influence of phase center uncertainty on baseline determination by using PacRim method proposed by JPL is analyzed. According to the analysis, the phase center uncertainty can cause a constant part of error to the result of baseline calibration. In order to deal with this problem, an improved calibration method on the basis of sensitivity equations and some ground moving targets, whose velocities are already known, is proposed in this paper. The simulation results show that our proposed calibration method has improved the accuracy of baseline calibration and has obviously prohibited the effect of antennas' phase center uncertainty.
