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1.
构建区域介质三维速度模型并以之获得准确的区域震相走时,是提高区域地震定位精度的重要手段之一.为充分利用已有的一维模型、GT事件、地质资料等实现三维模型构建,尝试基于目标区域内已有的部分局部一维模型,通过克里金空间插值建立初始三维模型,然后利用GT事件走时数据并参考其它地震地质资料对其不断进行修正,使得其走时偏差图与GT事件走时偏差图一致,进而获得能够提高区域地震定位精度的三维模型.使用不同模型进行的地震定位实验表明,以此方法建立的三维模型的定位偏差较初始模型减少约20％,较好地起到了减小区域震相走时残差,提高区域地震定位精度的作用. 相似文献
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基于局部一维模型与走时标定的区域 三维速度模型构建技术研究 总被引：1，自引：0，他引：1
构建区域介质三维速度模型并以之获得准确的区域震相走时, 是提高区域地震定位精度的重要手段之一. 为充分利用已有的一维模型、 GT事件、 地质资料等实现三维模型构建, 尝试基于目标区域内已有的部分局部一维模型, 通过克里金空间插值建立初始三维模型, 然后利用GT事件走时数据并参考其它地震地质资料对其不断进行修正, 使得其走时偏差图与GT事件走时偏差图一致, 进而获得能够提高区域地震定位精度的三维模型. 使用不同模型进行的地震定位实验表明, 以此方法建立的三维模型的定位偏差较初始模型减少约20%, 较好地起到了减小区域震相走时残差, 提高区域地震定位精度的作用. 相似文献
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基于偏移成像的微地震定位方法由于可避免走时拾取误差以及可实现自动化定位等优点被广泛应用.绕射叠加方法将能量沿走时曲线聚焦到空间网格点上,进行成像时需要搜索发震时刻.干涉成像方法利用互相关提取的走时差信息可避免搜索发震时刻,但定位结果受数据信噪比的影响较大.为了进一步提高干涉成像法的定位精度,本文提出一种同时使用互相关和自相关道集的全干涉成像方法,增加的自相关道集提取的S-P走时差可降低震源-检波器方向的定位误差,提高定位精度.单井监测的理论测试和实际数据的研究结果表明,全干涉成像的定位精度高于仅使用互相关道集的干涉成像方法,同时计算效率高于绕射叠加方法. 相似文献
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北斗区域卫星导航系统基本导航定位性能初步评估 总被引：10，自引：0，他引：10
北斗区域卫星导航系统(也称北斗2代1期)于2012年12月27日正式开始运行,系统由14颗卫星组成,包括5颗地球静止轨道卫星、5颗倾斜地球同步轨道卫星和4颗中圆地球轨道卫星.本文初步评估了北斗区域卫星导航系统建成运行后的基本导航定位性能,包括卫星可见性、位置精度衰减因子、伪距和载波相位观测量精度、单点定位和差分定位精度以及模糊度解算性能等.通过实验分析可知:北斗伪距和载波相位测量精度已与GPS处在同一水平,伪距测量精度约为33 cm,载波测量精度约为2 mm;北斗伪距单点定位水平精度优于6 m,高程精度优于10 m,已满足设计要求;北斗区域卫星导航系统已具备独立的双频RTK定位能力,其单历元双频模糊度解算成功率几乎与GPS相当;北斗载波相位差分定位精度与GPS相位差分定位处在同一水平,超短基线情况下,定位精度优于1 cm,而在短基线情况下优于3 cm;北斗与GPS组合定位时,模糊度解算的固定率和可靠性均显著提高;在短基线情况下,北斗/GPS组合载波相位差分动态定位精度相对于单一的GPS定位的改善可达20%以上;北斗单频伪距差分定位精度优于2.5 m,与GPS相比仍存在较大差距,其主要原因可能为北斗GEO卫星伪距多路径误差较大. 相似文献
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利用最小二乘法原理推导了多系统组合伪距单点定位的数学模型.然后,对不同组合模式(BDS、GPS、GLONASS、BDS/GPS、BDS/GLONASS、GPS/GLONASS和BDS/GPS/GLONASS)的单点定位进行解算和试验比较分析.试验结果表明:多系统(BDS/GPS/GLONASS)组合单点定位与单系统相比,多系统组合具有更多的可视卫星,从而获得了较小的PDOP值,随着截止高度角的增加,可见卫星数逐渐减少,定位精度也会随之降低.然而,在观测条件恶劣、截止高度角较大情况下,单系统和双系统定位精度都较差,三系统组合仍能获得比较好的定位精度,1 d内的定位精度均在10 m以下,优于GPS单点定位精度.使其在建筑物密集区、山区和卫星遮挡较为严重的恶劣条件下具有实际应用价值. 相似文献
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结合DTOA和DOA联合定位估计性好与牛顿迭代法收敛速度快的优点,提出了一种基于DTOA和DOA初值选取和牛顿法精确迭代的震源定位方法.经过野外实验和仿真,发现该方法能有效地提高震源定位的准确性.通过对影响震源定位精度因素分析,表明减小传感器基站站盐和初至波到时差测量误差可有效提高定位精度,相同同条件下,星型布站的定位精度最高. 相似文献
8.
从1985年到2000年间，中国及其邻近地区大约10％的地震事件属于重复性地震事件，并且彼此间不超过1km。我们对约14000个地震和爆炸的地震图做互相关，计算了相对到时约0．01 s，并使横向定位精度达到了100m～300m。这样的精度对于地震危险性研究、地震物理、禁止核试验的核查都非常重要。通过对已有的资料重复性信号的识别和测量，提高了定位精度，改进了在读取初至到时和定位方面目前程序的不精确性。 相似文献
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GPS定位中对流层折射率随机模型的研究 总被引：4，自引：1，他引：4
分析了ＧＰＳ相对定位中对流层折射的特点，概述了目前所采用的几种确定性参数对流层折射估计和随机过程参数对流层折射估计方法，根据实测数据处理结果，分析比较了几种确定性模型和随机过程模型对ＧＰＳ相对定位精度的改善作用。结果表明：对流层折射的多参数确定性模型和随机参数模型对基线分量的重复性，特别是高分程分量的重复性有明显改善，在大多数情况下，尤以随机参数模型为佳，其垂直分量的重复性精度较单参数模型可提高一 相似文献
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通过利用地震定位中的相对定位法对黑龙江省煤矿记录到的几个主要爆破事件进行精确定位,文中以牡丹江地区发生的爆破为例,详细介绍了定位的计算原理、计算方法和计算结果 ,并且与一般定位法相比较,使其在爆破事件的定位精度上得到提高. 相似文献
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基于四川GPS观测网络,本文提出采用低成本GPS-OEM板设计分米级差分GPS接收机。介绍四川GPS观测网络的工作原理,应用GPS观测网络改正由GPS轨道误差、电离层、对流层和大气折射引起的误差,将高精度的差分信息通过GPRS发给流动站来提高接收机的定位精度;论证了差分GPS的定位原理;最后提出整个系统的设计方案,用Thales DG14L OEM板处理GPS天线接收到的卫星信息,同时对GPRS天线接收数据中心差分信号进行差分运算。单片机控制软件采用汇编语言和C语言来编写。系统的实验结果表明,差分GPS接收机应用效果好,定位精度高,最重要的是降低了接收机的成本。 相似文献
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Preliminary assessment of the navigation and positioning performance of BeiDou regional navigation satellite system 总被引：7，自引：0，他引：7
YANG YuanXi LI JinLong WANG AiBing XU JunYi HE HaiBo GUO HaiRong SHEN JunFei DAI Xian 《中国科学:地球科学(英文版)》2014,57(1):144-152
BeiDou regional navigation satellite system(BDS)also called BeiDou-2 has been in full operation since December 27,2012.It consists of 14 satellites,including 5 satellites in Geostationary Orbit(GEO),5 satellites in Inclined Geosynchronous Orbit(IGSO),and 4 satellites in Medium Earth Orbit(MEO).In this paper,its basic navigation and positioning performance are evaluated preliminarily by the real data collected in Beijing,including satellite visibility,Position Dilution of Precision(PDOP)value,the precision of code and carrier phase measurements,the accuracy of single point positioning and differential positioning and ambiguity resolution(AR)performance,which are also compared with those of GPS.It is shown that the precision of BDS code and carrier phase measurements are about 33 cm and 2 mm,respectively,which are comparable to those of GPS,and the accuracy of BDS single point positioning has satisfied the design requirement.The real-time kinematic positioning is also feasible by BDS alone in the opening condition,since its fixed rate and reliability of single-epoch dual-frequency AR is comparable to those of GPS.The accuracy of BDS carrier phase differential positioning is better than 1 cm for a very short baseline of 4.2 m and 3 cm for a short baseline of 8.2 km,which is on the same level with that of GPS.For the combined BDS and GPS,the fixed rate and reliability of single-epoch AR and the positioning accuracy are improved significantly.The accuracy of BDS/GPS carrier phase differential positioning is about 35 and 20%better than that of GPS for two short baseline tests in this study.The accuracy of BDS code differential positioning is better than 2.5 m.However it is worse than that of GPS,which may result from large code multipath errors of BDS GEO satellite measurements. 相似文献
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In this paper, we derived a high-efficiency formula for calculating the precision of carrier phase relative positioning,analyzed the various factors that affect the positioning accuracy using the carrier phase, and proposed the concept of using a frequency dilution of precision to describe the quantitative effect of different frequency combinations on the positioning precision. To this end, we computed and plotted the global spatial distribution map of the relative positioning dilution of precision for single-day solution, half-hour solution, and single-epoch solution of the global positioning system(GPS), regional Beidou navigation satellite system(BDS2), future global Beidou navigation satellite system(BDS3), and their fusion systems.Using processing software with autonomous intellectual property rights(GCN and VENUS/ARSNet), we solved the measurement data and examined the positioning precision of the single-day solution and single-epoch solution of GPS and BDS2.The analysis demonstrated that the B1/B2 frequency positioning precision of BDS2 was better than that of L1/L2 frequency positioning of GPS, but the positioning precision of the BDS2 is worse than that of GPS over most of the service region of the BDS2. Further, the positioning precision of BDS3 is better than that of GPS in the Asia-Pacific region, while it is the opposite in other regions. Based on these conclusions, we put forth some optimization recommendations regarding the signal frequency of the navigation system and GPS measurement standards to serve as references for optimizing the system performance and formulating standards. 相似文献
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讨论了实时精密单点定位的若干关键技术,着重研究了实时精密钟差估计算法;利用全球40个IGS跟踪站连续、实时的观测数据流进行实时精密卫星钟差估计,解算出的实时精密钟差与CODE事后精密钟差具有较好的一致性,二者互差的RMS优于0.2 ns.采用实时估计的卫星钟差和IGS发布的超快速精密卫星轨道进行实时精密单点定位模拟实验,结果表明：经过大约15~30 min初始化后,实时精密单点定位滤波收敛之后水平方向的定位精度优于5 cm,高程方向的精度优于10 cm,能满足在该精度级别的实时用户的定位需求.处理汶川地震期间震区的GPS观测数据,结果表明实时精密单点定位能够探测地震发生期间的地面同震位移. 相似文献
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Engineering vibration monitoring by GPS： long duration records 总被引：1，自引：0，他引：1
Monitoring the performance of any structure requires real-time measurements of the change of position of critical points.Different techniques can be used for this purpose,each one offering advantages and disadvantages.The technique based on satellite positioning systems(GPS,GLONASS and the future GALILEO)seems to be very promising at least for long period structures.The GPS in particular provides sampling rates that are able to track dynamic displacements with high accuracy.Its service ability is indepen... 相似文献
18.
《Journal of Atmospheric and Solar》2008,70(15):1985-1994
We investigated failures in the global positioning system (GPS) performance produced by solar radio bursts with unprecedented radio flux density during the X6.5 and X3.4 solar flares on 6 and 13 December 2006, respectively. The effect of these events on GPS was compared to that of the X17.2 solar flare of 28 October 2003. Significant experimental evidence was found that high-precision GPS positioning on the Earth's entire sunlit side was partially disrupted for more than 10–15 min on 6 and 13 December 2006. The high level of phase slips and count omissions resulted from the wideband solar radio noise emission. Our results provide serious grounds for revising the role of space weather factors in the functioning of modern satellite systems and for considering these factors more carefully in practice. Similar failures in the operation of satellite navigation systems (GPS, GLONASS, and GALILEO) can be fatal for operating safety systems as a whole and lead to great financial losses. Another important conclusion of our investigation concerns the continuous calibrated monitoring of the level of the solar radio emission flux. This monitoring involved a large number of solar radio spectrographs and allowed us to estimate the solar radio noise level in the range of the GPS–GLONASS–GALILEO frequencies. 相似文献
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GPS技术在监测地震与地壳运动中已经得到应用，北京市地震局在北京市2002年启动建设的全球卫星定位综合应用服务系统基础上，于2003年开始GPS形变监测工作系统的建设，这是一个小区域连续的高密度GPS形变监测工作系统，获取高精度的北京市GPS基准站地心三维坐标，为地震监测和地壳运动的科学研究提供良好的GPS数据素材。 相似文献
20.
The state of the ionosphere affects the operational stability of satellite radio navigation systems. The dense network of
GEONET GPS sites on the territory of Japan allows to conduct a thorough investigation of the stability of system operation
at mid-latitudes in different heliogeophysical conditions. This paper considers deterioration in the accuracy of GPS system
positioning due to the effect of a large-scale ionospheric disturbance (an ionospheric bubble) over Japan on February 12,
2000. 相似文献