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1.
利用“中国地壳运动观测网络(二期)”245个GPS连续观测站及其他站的大量观测结果,采用离震中很远的7个GPS站作为位错参考框架,得到2011年3月11日东日本Mw9.0大地震的同震水平位移和应变。此种参考框架的位移场解,符合弹性位错模型离震中很远且水平位移接近于0的要求,不仅有利于位错模型反演,也有利于合理分析此次大地震同震水平位移的影响范围。地震前后区域参考框架下远场GPS连续观测位移时间序列和同震位移弹性位错模型反演结果表明,东日本大地震同震水平位移既是地震断层破裂的结果,也是远场震前数月或数年水平位移的弹性回跳,据此可以进一步确认这些站震前水平位移前兆异常。由于这些震前异常位移中亦包含了同震位移量(方向相反),因此,弹性位错模型为定量研究大地震前远场地壳运动异常提供了一种理论模型。位错参考框架中的同震位移及其位错模型和区域参考框架的位移时间系列的综合研究有助于对此次大地震地壳运动异常的认识。这种持续时间为数月至数年的弹性形变异常,可以为大地震的中短期预测提供依据。 相似文献
2.
针对强震仪与GPS各自的优点与缺陷，以2016年意大利Mw 6.0级地震为例，探讨了利用Kalman滤波融合GPS与强震仪数据实时监测中等强度地震引起的瞬时地壳形变的可行性与优势。Kalman滤波获取的位移波形以GPS数据作为整体趋势，细节部分用强震仪数据进行描述，融合后的位移波形精度较高，能够准确和细致地描述地震引起的地表动态形变；与此同时，Kalman滤波位移波形也能够准确地探测中等强度地震引起的同震永久阶跃；Kalman滤波位移波形的功率谱在低频部分与GPS位移波形的功率谱密度相似，在高频部分与强震仪位移波形的功率谱密度相似，表明Kalman滤波结合了GPS与强震仪各自的优点；交叉小波分析表明，Kalman滤波获取的位移波形与GPS、强震仪数据呈现较强的正相关性，小波相似值均在0.8以上。以上结果表明，融合GPS与强震仪数据可以结合二者各自的优点，弥补各自的缺陷；融合GPS与强震仪数据可以有效探测中等强度地震引起的瞬时地壳形变。 相似文献
3.
利用动态定位模块Track进行GPS单历元定位研究 总被引：1，自引：0，他引：1
在研究GPS单历元定位方法基础上,利用GAMIT GPS数据处理软件中的动态定位模块Track,分别得到了动船的运动轨迹和2011年3月日本地震发生后4个IGS站的位移量。实验结果表明：Track模块解算动态GPS数据能得到清晰的动船运动轨迹;采用TRACK模块解算地震发生时的GPS观测数据能够得到地震后的位移特征,且能有效探测主震发生时间。 相似文献
4.
利用动态精密单点定位技术,分析了日本仙台大地震对日本及中国境内若干GPS基准台站的影响。结果表明,采用动态精密单点定位技术能准确地反映GPS台站的受损程度,有效地探测地震发生时刻及其震后位移。 相似文献
5.
利用国家重大科学工程中国地壳运动观测网络的两期GPS观测值得到川滇区域内测站的速度。以这些速度为约束，基于数值流形模型拟合了川滇地区的速度场。它很好地结合了块体内部的连续变形和块体间的非连续变形。较非连续变形分析模型，地质构造速度模型和配置拟合模型等更真实模拟了地壳运动速度场，为相关地学研究提供了很好的基础。 相似文献
6.
2021年5月22日,青海省玛多县发生M7.4级地震,地震对区域基准站造成了影响. 本文收集了距震中400 km以内的青海省全球卫星导航系统(GNSS)连续运行参考站(CORS)的高频观测数据,以国际GNSS服务 (IGS)站和陆态网为参考基准,分别采用静态模式和动态模式分析了震后地表三维形变. 结果表明:站点位移量级随震中距的加大而呈现衰减趋势,其中距震中约35 km的江多站(JDUO)产生东偏南28.0 cm的永久性位移. 整体来讲,地震对100 km内的震源区的影响表现为走滑型运动,与震源机制相吻合,区域运动特征整体表现为拉张运动,北西-南东(NW-SE)向拉张和北东-南西(NE-SW)向挤压. 相似文献
7.
基于区域参考站网的网络实时动态定位(real-time kinematic,RTK)方法是实现全球定位系统(global positioning system,GPS)、北斗卫星导航系统(BeiDou satellite navigation system,BDS)高精度定位的主要手段。研究了一种长距离GPS/BDS双系统网络RTK方法,首先采用长距离参考站网GPS/BDS多频观测数据确定宽巷整周模糊度,利用引入大气误差参数的参数估计模型解算GPS/BDS双差载波相位整周模糊度;然后按照长距离参考站网观测误差特性的不同,分类处理参考站观测误差,利用误差内插法计算流动站观测误差,以改正流动站GPS/BDS双系统载波相位观测值的观测误差;最后使用流动站多频载波相位整周模糊度解算方法确定GPS/BDS载波相位整周模糊度并解算位置参数。使用长距离连续运行参考站(continuously operating reference stations,CORS)网的实测数据进行实验,结果表明,该方法能够利用长距离GPS/BDS参考站网实现流动站的厘米级定位。 相似文献
8.
A grid-based tropospheric product for China using a GNSS network 总被引：1，自引：0，他引：1
Tropospheric delay accounts for one source of error in global navigation satellite systems (GNSS). To better characterize the tropospheric delays in the temporal and spatial domain and facilitate the safety-critical use of GNSS across China, a method is proposed to generate a grid-based tropospheric product (GTP) using the GNSS network with an empirical tropospheric model, known as IGGtrop. The prototype system generates the GTPs in post-processing and real-time modes and is based on the undifferenced and uncombined precise point positioning (UU-PPP) technique. GTPs are constructed for a grid form (\(2.0{^{\circ }}\times 2.5{^{\circ }}\) latitude–longitude) over China with a time resolution of 5 min. The real-time GTP messages are encoded in a self-defined RTCM3 format and broadcast to users using NTRIP (networked transport of RTCM via internet protocol), which enables efficient and safe transmission to real-time users. Our approach for GTP generation consists of three sequential steps. In the first step, GNSS-derived zenith tropospheric delays (ZTDs) for a network of GNSS stations are estimated using UU-PPP. In the second step, vertical adjustments for the GNSS-derived ZTDs are applied to address the height differences between the GNSS stations and grid points. The ZTD height corrections are provided by the IGGtrop model. Finally, an inverse distance weighting method is used to interpolate the GNSS-derived ZTDs from the surrounding GNSS stations to the location of the grid point. A total of 210 global positioning system (GPS) stations from the crustal movement observation network of China are used to generate the GTPs in both post-processing and real-time modes. The accuracies of the GTPs are assessed against with ERA-Interim-derived ZTDs and the GPS-derived ZTDs at 12 test GPS stations, respectively. The results show that the post-processing and real-time GTPs can provide the ZTDs with accuracies of 1.4 and 1.8 cm, respectively. We also apply the GTPs in real-time kinematic GPS PPP, and the results show that the convergence time of the PPP solutions is shortened. These results confirm that the GTPs can act as an efficient information source to augment GNSS positioning over China. 相似文献
9.
广域实时精密定位与时间服务已成为GNSS应用领域研究热点,目前国内外学者围绕其模型算法已展开大量的研究。本文重点论述广域实时精密定位与时间服务数据的处理方法和服务系统,给出了基于不同基准约束的卫星钟差解算数学模型,提出通过引入外接原子钟测站、标准时间源(UTC/BDT)等不同时间基准,构建卫星拟稳基准、外接原子钟跟踪站拟稳基准及标准时间源等约束下的钟差解算模型,分析了时间基准对精密单点定位和精密单点授时的影响。本文采用实时卫星轨道、钟差、相位偏差、电离层延迟等服务产品及跟踪站实时数据,验证了系统产品可靠性及终端定位与时间服务性能。实测结果表明:GPS轨道径向精度1.8 cm,钟差STD精度约0.05 ns;BDS-3轨道径向精度6.7 cm,钟差STD精度优于0.1 ns;GPS和BDS-2电离层改正精度分别为0.74 TECU与1.03 TECU。基于该产品实现了用户端PPP、PPP-RTK及PPT、PPT-RTK服务,满足了用户实时厘米级定位和优于0.5 ns的单站时间传递服务,当采用GPS+BDS-2 PPP-RTK解算时,平面收敛至5 cm约需要12 min。 相似文献
10.
利用陆态网络东北地区的6个GPS基准站地震期间的观测数据反演了日本本州东海岸9.0级强震区域地表的瞬时形变过程,应用160多个陆态网络基准站以及IGS跟踪站的GPS观测数据解算获得中国大陆地区的远场同震位移。将测站按照中国大陆主要构造带(区)进行分配统计可知,东北地区同震位移最大,平均接近20mm;首都圈与郯-庐带及周围地区平均同震位移也在10mm左右;距离震中比较远的鄂尔多斯及周围、阿尔金-祁连山-阿拉善、新疆等地区也受到了该地震的影响,在东方向发生了5mm左右的位移,并且以上地区的优势方向都为东方向;而本次地震对中国的华南(包括南海)以及青藏等地区基本没有影响。这些解算结果对进一步研究地震动力学特征及判定未来地震趋势提供了详实的实测依据。 相似文献
11.
日本3·11特大地震的GPS震时和震后响应 总被引：1，自引：1，他引：0
借助PPP软件,利用位于日本及周边国家的IGS跟踪站和国家海洋局GPS业务观测站数据,提取2011年3月11日日本里氏9.0级特大地震的震时、震后地表震动信息和水汽信息。首先采用动态PPP方法得到GPS站点的震时水平运动轨迹、震时三维坐标时间序列以及站点上空大气可降水量的动态变化;然后采用静态PPP方法得到GPS站点震前和震后的单天解坐标。通过对计算结果进行分析和比较,揭示了GPS站点的震时地表三维形变过程和震后地表永久性形变,验证了日本震后灾区的降雪过程,为GPS技术用于地震监测和灾害预警提供有价值的基础资料。 相似文献
12.
随着精密定位技术的发展,高频GPS已能够精确记录地表位移数据,研究高频GPS能为地震预警工作做出一定补充.针对目前地震预警中单站预警误报率高的问题引入深度学习技术,利用长短期记忆网络(LSTM)联合周边区域台站对单台站进行预警以达到减少误报的目的.首先通过对新西兰南部地区1 Hz高频GPS数据进行解算得到多个台站无震时间序列,再利用该数据训练网络得到融合区域特征的高精度模型.该模型可以对无震时间序列进行预测并动态制定阈值区间,当实际观测值超出置信区间则判定异常.通过与传统短时窗平均/长时窗平均算法(STA/LTA)及未融合区域特征的单站模型进行对比,结果表明:融合区域特征的单站模型可有效减少误报,在多个台站的无震长序列上较传统方法表现优异,具有一定的应用价值. 相似文献
13.
汶川地震震后GNSS形变分析 总被引：1，自引：0，他引：1
采用国际通用高精度数据处理软件对1999—2015年汶川地震震后龙门山断裂两侧分布的109个GNSS连续站和区域站资料进行数据处理与分析,得到各测站点水平向坐标时间序列。考虑2013年芦山地震同震位移影响,通过时间序列分析,获取震后该区域109个测站在2010—2015年间累计震后形变场,断裂带上盘靠近震中的近场区域,水平向最大震后位移达到5~7 cm。基于震后黏弹性松弛模型,通过格网搜索,根据3种不同破裂模型分别反演龙门山断裂上盘中上地壳最佳弹性层厚度估值与下地壳/上地幔黏弹性层最佳黏滞系数,获取3种不同破裂模型在2010—2015年间震后形变观测值与模拟值分布。根据模型二反演得到的模型参数,推估汶川地震在未来几十年内对周边区域地壳形变影响,其中仅2018—2058年40年尺度累计震后位移最大能达到19 cm。 相似文献
14.
15.
Steffen Schön 《GPS Solutions》2007,11(2):107-117
GPS is a promising tool for real-time monitoring of deformations of slopes or large structures. However, remaining systematic
effects in GPS phase observations after double differencing and application of a priori models affect the resulting coordinates.
They complicate the proper separation of the actual deformations from pseudo-deformations induced by the systematic effects.
This paper shows that for small monitoring networks (baseline lengths <5 km) only affine distortions of the network geometry
are generated by the remaining distance dependent systematic effects, e.g. unmodelled tropospheric and ionospheric propagation
effects, or satellite orbit errors. Hence, a generic correction model is given by a three-dimensional affine transformation
involving a maximum of 12 transformation parameters. For the determination of these parameters, four high quality GPS stations
are necessary which are not affected by the actual deformations to be monitored. Based on the analysis of network geometries
of synthetic GPS networks with large height differences and considering the physics of the GPS observations it is shown, however,
that less than 12 parameters are sufficient for the computation of the corrections. The proposed 8 parameter model was applied
to the GPS monitoring network of the Gradenbach landslide. For this small network with large height differences, it was shown
that the distortions can be reduced by about 75%. 相似文献
16.
The anomaly phenomenon of broadcast ionospheric model coefficients of the Global Positioning System (GPS) is revealed after analyzing the navigation file data collected from all the IGS (International GNSS Service) stations worldwide over a 22-year period (1992–2013). GPS broadcast ionospheric coefficients widely used by many single-frequency users to correct the ionosphere errors for numerous GPS applications are usually believed to have only one set/version per day. However, it is found that GPS receivers from the IGS network can report as many as eight sets/versions of ionospheric coefficients in a day. In order to investigate the possible factors for such an anomalous phenomenon, the relationship between the number of coefficient sets and solar cycle, the receiver geographic locations, and receiver types/models are analyzed in detail. The results indicate that most of the coefficients show an annual variation. During the active solar cycle period from mid-1999 to mid-2001, all of the coefficients extracted from IGS navigation files behaved anomalously. Our analysis shows that the anomaly is also associated with GPS receiver types/models. Some types/models of GPS receivers report one set/version of ionospheric coefficients daily, while others report multiple sets. Our analysis also suggests that the ionospheric coefficient anomaly is not necessarily related to ionospheric scintillations. No correlation between the anomaly and geographic location of GPS receivers has been found in the analysis. Using the ionospheric coefficient data collected from 1998 to 2013, the impact of ionospheric coefficient anomaly on vertical total electron content (VTEC) calculation using the Klobuchar model has been evaluated with respect to the Global Ionospheric Maps generated by the Center for Orbit Determination in Europe. With different sets of coefficients recorded on the same day, the resulting VTEC values are dramatically different. For instance on June 1, 2000, the largest VTEC at one of our test stations can be as large as 153.3 TECu (total electron content unit) using one set of coefficients, which is 16.36 times larger than the smallest VTEC of 9.37 TECu computed from using another set of coefficients. 相似文献
17.
精密卫星钟差加密方法及其对星载GPS低轨卫星定轨精度影响 总被引：7，自引：0，他引：7
韩保民 《武汉大学学报(信息科学版)》2006,31(12):1075-1078
系统分析、比较了几种精密卫星钟差加密方法，研究了利用全球分布的IGS永久跟踪站的GPS观测数据估计高采样率卫星钟差参数的原理与方法，并将各种卫星钟差加密方法得到的结果与IGS数据分析中心估计的卫星钟差结果相比较。最后将不同加密方法得出的精密卫星钟差结果用于基于星载GPS双频非差观测值的CHAMP低轨卫星的定轨，并将不同方法得到的定轨精度进行比较。结果表明，利用地面跟踪站的GPS观测数据，可高精度、高密度地估计GPS卫星钟差，估计精度可达0．1～0．5ns。经地面GPS跟踪站数据估计的GPS卫星钟差，应用于基于PPP方法的低轨卫星定轨，其定轨精度在10cm以内。 相似文献
18.
吴继忠 《武汉大学学报(信息科学版)》2011,(4):437-440
2010-04-04墨西哥Baja California(32.259°N,115.287°W)Ms 7.2级地震发生在GPS连续观测站及钻孔应变仪相当密集的区域,利用GPS监测数据计算出了若干站点地震前后的位移量。地壳变形分析结果表明,离震中近的观测站变形量普遍较大,最大可达0.2m,大部分观测站明显向东南方向运动。通过选择较稳定的观测站作为参考站,计算了4观测站的动态变形序列,同时得到地震波的传播速度为3.2km/s,与应变观测计算结果比较吻合。 相似文献
19.
Vertical deformations from homogeneously processed GRACE and global GPS long-term series 总被引：3，自引：1，他引：2
Volker Tesmer Peter Steigenberger Tonie van Dam Torsten Mayer-Gürr 《Journal of Geodesy》2011,85(5):291-310
Temporal variations in the geographic distribution of surface mass cause surface displacements. Surface displacements derived
from GRACE gravity field coefficient time series also should be observed in GPS coordinate time series, if both time series
are sufficiently free of systematic errors. A successful validation can be an important contribution to climate change research,
as the biggest contributors to mass variability in the system Earth include the movement of oceanic, atmospheric, and continental
water and ice. In our analysis, we find that if the signals are larger than their precision, both geodetic sensor systems
see common signals for almost all the 115 stations surveyed. Almost 80% of the stations have their signal WRMS decreased,
when we subtract monthly GRACE surface displacements from those observed by GPS data. Almost all other stations are on ocean
islands or small peninsulas, where the physically expected loading signals are very small. For a fair comparison, the data
(79 months from September 2002 to April 2009) had to be treated appropriately: the GPS data were completely reprocessed with
state-of-the-art models. We used an objective cluster analysis to identify and eliminate stations, where local effects or
technical artifacts dominated the signals. In addition, it was necessary for both sets of results to be expressed in equivalent
reference frames, meaning that net translations between the GPS and GRACE data sets had to be treated adequately. These data
sets are then compared and statistically analyzed: we determine the stability (precision) of GRACE-derived, monthly vertical
deformation data to be ~1.2 mm, using the data from three GRACE processing centers. We statistically analyze the mean annual
signals, computed from the GPS and GRACE series. There is a detailed discussion of the results for five overall representative
stations, in order to help the reader to link the displayed criteria of similarity to real data. A series of tests were performed
with the goal of explaining the remaining GPS–GRACE residuals. 相似文献
20.
近年来,有研究发现在GPS测站坐标时间序列中既存在白噪声,也存在有色噪声。为了研究有色噪声对东南极区域GPS测站三维速度估计的影响,本文使用GAMIT/GLOBK10.5软件对东南极区域6个连续GPS测站2005—2014年的实测数据进行解算和平差,并利用最大似然法（MLE）分别估计了在两种假设噪声模型条件下的测站三维运动速度及其不确定性。结果表明：在进行参数估计时,考虑两种有色噪声（闪烁噪声和随机游走噪声）对东南极区域GPS测站三维速度估计的量级影响不大,水平方向最大影响量级为0.3 mm/a,垂直方向最大影响量级为0.8 mm/a;但如果不考虑有色噪声,会严重低估参数估计的真实不确定性。 相似文献