基于“北斗”观测数据的C波段双向卫星时间频率传递中的电离层改正     

孔垚  杨旭海  孙保琪  李志刚  陈亮 《时间频率学报》2012,35(3):148-155

为了提高C波段双向卫星时间频率传递(TWSTFT)精度,用载波相位观测值平滑伪距的方法,计算电离层延迟对C波段双向卫星时间频率传递的影响。在临潼站和喀什站观测北斗G3星并进行双向比对。该实验结果表明,实验期间C波段双向卫星时间频率传递中电离层延迟影响的最大值为0.47 ns。  相似文献   

低频地波场强和二次相位因子计算的可视化实现   总被引：1，自引：1，他引：0  

王娜  苏建峰  李瑞敏 《时间频率学报》2012,35(1):29-37

准确计算地波场强和时延是利用BPL或罗兰-C定时的关键技术之一。利用VC++面向对象和可视化的程序设计实现了低频范围内任意距离上场强和二次相位因子的计算。MicrosoftWindows图形用户界面使得工程人员操作起来简单易懂,更加具有实用性。比较表明,该程序的计算结果与现有的数据吻合得非常好,计算结果准确度较高。  相似文献   

岩石圈流变学：一种研究地球深部岩体变形的新方法          下载免费PDF全文

余尚江  刘稳航  杨源祯 《江苏地质》2013,37(4):530-534

岩石圈流变学是大陆岩石变形的主导因素之一,是一种研究地球深部岩体变形的新方法。简要介绍流变学对大陆动力学研究的影响,并对当前流变学研究进展进行评述。岩石圈流变学在岩石圈地层、造山带和大型盆地动力学和动力学特征研究中的应用非常广泛。近年来,岩石圈流变学在脆-塑性转换、岩石流变含水性、“三明治”结构及岩石流变律等方面有重大进展。最后,指出目前岩石圈流变学还存在一些亟待解决的问题,如时间因素。  相似文献   

An estimation method for effective stress changes in a reservoir from 4D seismics data     

Alejandro Garcia  Colin MacBeth 《Geophysical Prospecting》2013,61(4):803-816

Advances in seismics acquisition and processing and the widespread use of 4D seismics have made available reliable production‐induced subsurface deformation data in the form of overburden time‐shifts. Inversion of these data is now beginning to be used as an aid to the monitoring of a reservoir's effective stress. Past solutions to this inversion problem have relied upon analytic calculations for an unrealistically simplified subsurface, which can lead to uncertainties. To enhance the accuracy of this approach, a method based on transfer functions is proposed in which the function itself is calibrated using numerically generated overburden strain deformation calculated for a small select group of reference sources. This technique proves to be a good compromise between the faster but more accurate history match of the overburden strain using a geomechanical simulator and the slower, less accurate analytic method. Synthetic tests using a coupled geomechanical and fluid flow simulator for the South Arne field confirm the efficacy of the method. Application to measured time‐shifts from observed 4D seismics indicates compartmentalization in the Tor reservoir, more heterogeneity than is currently considered in the simulation model and moderate connectivity with the overlying Ekofisk formation.  相似文献   

Estimation of pore‐pressure change in a compacting reservoir from time‐lapse seismic data     

Margarita Corzo  Colin MacBeth  Olav Barkved 《Geophysical Prospecting》2013,61(5):1022-1034

An approach is developed to estimate pore‐pressure changes in a compacting chalk reservoir directly from time‐lapse seismic attributes. It is applied to data from the south‐east flank of the Valhall field. The time‐lapse seismic signal of the reservoir in this area is complex, despite the fact that saturation changes do not have an influence. This complexity reflects a combination of pressure depletion, compaction and stress re‐distribution throughout the reservoir and into the surrounding rocks. A simple relation is found to link the time‐lapse amplitude and time‐shift attributes to variations in the key controlling parameter of initial porosity. This relation is sufficient for an accurate estimation of pore‐pressure change in the inter‐well space. Although the time‐lapse seismic estimates mostly agree with reservoir simulation, unexplained mismatches are apparent at a small number of locations with lower porosities (less than 38%). The areas of difference between the observations and predictions suggest possibilities for simulation model updating or a better understanding of the physics of the reservoir.  相似文献   

基于GAMIT软件的对流层延迟量解算分析     

贾伟  潘元进  何美琳  覃辉 《地理空间信息》2013,11(1):46-48,12

高精度数据处理软件是GPS数据解算的重要组成部分,也是GPS应用于各项研究领域的前提。基于GAMIT软件,通过研究分析其在解算时的关键技术,对广西CORS数据进行了解算,得出了其天顶方向延迟量。  相似文献   

Multi-Scale Visualisation of Inbound and Outbound Traffic Delays in London     

《The Cartographic journal》2013,50(4):323-329

Abstract

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Traffic delays can be used to quantify traffic congestion on the road. However, traffic delay data itself cannot provide readily useful content about congestion directly. The aim of this research is to develop a multi-scale visualisation of traffic delay (excess travel time in minutes per kilometre) derived from automatic number plate reading (ANPR) data, to enable traffic commuting patterns to and from Central London to be understood and analysed further.  相似文献   

基于多项式拟合的移去恢复法求解对流层天顶延迟的研究     

赵静  尹慧芳  党亚民  薛树强  杨强 《测绘科学》2013,38(4)

本文针对基于区域GPS网内插流动站对流层天顶延迟(ZTD)时存在的问题,提出了基于多项式拟合的移去恢复法.该方法利用对流层天顶延迟与高程之间的强相关性,通过多项式拟合将对流层天顶延迟中与高程相关的信息移去后再进行内插求解.采用SCIGN的GPS数据进行实验,结果表明:基于多项式拟合的移去恢复法的插值精度明显高于传统的反距离加权直接内插法,特别对于高程明显偏离参考站总体高程的流动站具有较好的改进效果.  相似文献   

精密单点定位中卫星星历对天顶对流层延迟估计的影响     

徐爱功  徐宗秋  隋心 《测绘科学》2013,38(2):19-21

为了分析不同卫星星历对天顶对流层延迟估计的影响,本文选取不同的卫星星历产品分别进行静态精密单点定位试验,估计天顶对流层延迟,并与IGS发布的天顶对流层延迟产品相比。结果表明,采用最终星历、快速星历和超快星历实测部分时,天顶对流层延迟的平均RMS值分别为4.5mm、4.3mm和4.6mm,估计精度一致。而采用超快星历外推部分时,平均RMS值为6.3mm,估计精度略低。  相似文献   

精密单点定位中对流层延迟参数的相关性研究     

徐宗秋  徐爱功  高扬  徐辛超 《测绘科学》2013,38(5):8-10,65

为了确定对流层延迟参数的自相关性及其与坐标参数的互相关性,本文研究采用随机卡尔曼滤波进行精密单点定位解算。根据自相关原理计算出对流层天顶延迟误差的自相关函数,采用4种经验函数模型分别对自相关函数进行拟合,结果表明exponential-cos为最佳拟合模型;对对流层天顶延迟误差与坐标垂直分量误差的互相关性进行了分析,结果表明二者显著负线性相关;坐标垂直分量误差波动幅度是对流层天顶延迟误差波动幅度的4倍左右;卫星截止高度角越低,参数相关性越强。  相似文献