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基于D-InSAR的1993-1995年苏州市地面沉降监测 总被引：4，自引：2，他引：4
本文利用欧洲空间局ERS-1/2 SAR数据,通过SAR差分干涉测量(D-InSAR)处理得到1993-1995年苏州市地面沉降场测量值.地面水准测量数据的验证分析表明,差分干涉测量值与水准测量值的相关度达0.943,标准误差均值为0.1706.雷达差分干涉测量精度可达5mm(以水准测量代表地面形变的真实情况).研究结果表明,D-InSAR技术进行城市地面沉降方面监测和时空演化特征研究具有很大的优势,同时可用于其它类型城市地质灾害的监测. 相似文献
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高精度的卫星轨道确定是卫星应用的基础和保证,本文以新一代DORIS接收机观测数据DORIS 3.0的相位观测数据为基础,研究了相位观测数据与传统的DORIS距离变化率数据的转换方法,并以JASON-2卫星为例,基于卫星动力学定轨原理,分析了不同数据类型、不同定轨方案得到的卫星轨道精度.结果表明,1)利用3天弧段的DORIS 2.2格式距离变化率数据和数据文件提供的相位中心偏差改正,或者采用模型对天线相位中心偏差进行改正并同时对地面测站进行偏心改正时,两种方案得到的轨道三维位置精度基本一致,均优于8.7cm,说明新一代DORIS接收机相位中心稳定,变化较小,采用模型进行偏差修正完全能够满足定轨精度要求.2)采用3.0格式的DORIS数据以及天线相位中心偏差修正模型和地面测站偏心改正模型时,得到的卫星定轨精度略有降低,大约为9.2cm;SLR校核残差约为6.5cm(均方根误差).3)采用2.2和3.0两种格式的DORIS数据,利用不同的定轨方案对JASON-2卫星进行精密定轨,均可以达到2cm左右的径向定轨精度,不同的定轨方案对径向定轨精度的影响可忽略不计.因此,对于最关心卫星径向定轨精度的海洋测高卫星而言,采用本文的数据格式转换方法和定轨方案,完全可以满足其定轨任务需求. 相似文献
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介绍了差分干涉测量的原理、差分干涉数据对的选取方法,以及三轨法差分干涉测量数据处理的流程.利用星载合成孔径雷达差分干涉(D-InSAR)测量技术和ENVISAT ASAR雷达数据对2003年12月26日伊朗Bam 6.5级地震引起的地表形变场进行了测量试验,成功地获取了Bam地震的蝴蝶状的同震形变场生成了地表形变的等值线图,并且根据相干图确定了地震造成破坏最严重的区域的位置、分布及面积.试验证明D-InSAR技术是地表形变测量和地震研究的一个强大和有效的工具. 相似文献
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本文利用欧洲空间局ERS-1/2 SAR数据，通过SAR差分干涉测量（D-InSAR)处理得到1993-1995年苏州市地面沉降场测量值。地面水准则测量数据的验证分析表明，差分干涉测量值与水准则值量值的相关度达0.943，标准误差均值为0.1706。雷达差分干涉测量精度可达5mm（以水准则量代表地面形变的真实情况）。研究结果表明，D-InSAR技术进行城市地面沉降方面监测和时空演化特片研究具有很大的优势，同时可用于其它类型城市地质灾害的监测。 相似文献
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时序雷达干涉图中的永久散射体(PS)可看作“天然GPS点”, 以构成网络用于监测长期的地表形变. 本文提出采用邻接矩阵拓扑模型对基于Delaunay剖分算法生成的PS网络进行基线识别, 并采用时序相干最大化算法求解PS基线的线性形变速度增量和高程误差增量. 该数据模型和计算方法被应用于探测香港地区2006~2007年间的区域地表沉降. 实验研究采用由Envisat卫星ASAR传感器对该地区成像所获取的时序SAR影像作为数据源, 并联合该地区12个GPS连续运行参考站的观测数据予以大气修正和地面控制. 实验结果表明, 该模型和方法应用于地表形变测量是有效的和可靠的, PS网络方法探测地面沉降的精度约为±2.0 mm/a. 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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差分合成孔径雷达干涉测量技术(differential interferometry synthetic aperture radar,D-InSAR)是地震形变监测的一种重要方法,但是其存在视线向(line of sight,LOS)模糊的问题,即D-InSAR测量的形变场并不是地表真实的垂直向、东西向、南北向形变场,而是地表 相似文献
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2016年2月6日台湾西南部高雄市美浓区发生了MW6.4地震.本文结合ALOS2卫星升降轨、Sentinel-1A升轨SAR数据,采用两轨差分干涉技术获取了该区域的同震形变场,形变结果表明震中西北部以抬升为主,最大视线向形变量约为11.2 cm.基于均匀位错模型和多峰值粒子群（MPSO）算法,利用InSAR和GPS形变数据联合反演了美浓地震的断层几何参数,结果表明震源中心位于22.920°N,120.420°E,深度约12 km,发震断层长度约15 km,走向角307°,倾角16.5°,平均滑动角为51.5°,此次地震是以逆冲倾滑兼左旋走滑的破裂模式.利用格网迭代搜索法得到最优倾角为15.7°,GPS和InSAR最优权比为18：1,最优平滑因子为0.06.基于非均匀位错模型,利用非负最小二乘方法进行线性反演,结果显示最大倾滑和走滑量分别为51.7 cm和55.3 cm,对应矩震级为MW6.38,略小于GCMT （MW6.4）的结果.通过与已有文献的比较和对该区域断层构造的分析,发现美浓地震的发震断层为单一断层的解释更为合理,我们推测发震断层是位于左镇、后甲里等断层之间的一条东南-西北走向往东北倾斜的盲断层,并初步推测2010年MW6.3甲仙地震也同该断层有关. 相似文献
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针对InSAR技术在形变监测领域中的应用,本文从分析D-InSAR的干涉机理对其约束条件出发,重点研究空间去相关和形变梯度这两个关键指标对形变信息提取的影响.研究针对不同系统参数的传感器来展开,并论证这两个因素对干涉测量的限制.本文的创新性工作主要集中在以下几个方面: (1)分析了各传感器参数下的临界坡度范围,进而确立了SAR传感器监测的无信息区域;(2)证明了在植被覆盖区,相干性分解必须考虑体散射分量,并依此对模型进行了修正;(3)明确了形变梯度与相位梯度的差异以及两者的函数关系,并将入射角引入形变梯度函数模型.(4)通过模拟数据和真实数据比较各传感器在不同条件下形变监测的优缺点,在统计分析的基础上进一步验证结论.本文的研究是对干涉测量条件的进一步补充,对于理解干涉成像机理、完善InSAR数值计算模型(形变梯度模型和相干性分解模型)以及帮助研究人员根据研究区域特征选择合适的InSAR数据具有一定的参考价值. 相似文献
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固体地球潮汐(Solid earth tide,SET)在地表产生的径向位移可达40～50 cm,形变梯度可达2 cm/100 km,是各种精密大地测量和地球物理观测必须考虑的因素之一.随着星载合成孔径雷达干涉测量(Interferometric synthetic aperture radar,InSAR)地表形变监测范围的不断增大以及对精度要求不断提高,固体潮位移对InSAR观测的影响不容忽视.本文利用固体潮位移理论模型,根据InSAR测量基本原理和Sentinel-1卫星成像参数,模拟了固体潮位移InSAR相位,定量分析了其时空分布特征,并以我国江汉平原和北美大平原的Sentinel-1数据为例,探讨了固体潮位移InSAR相位对广域地表形变监测的影响.结果表明:(1)固体潮位移对InSAR广域地表形变监测存在较大影响,在250 km×250 km范围中,以C波段为例,其相位变化可达12 rad(对应52 mm视线向形变);(2)固体潮位移相位在中低纬度(60°S—60°N)地区变化较大,两极地区较小,且在时间上具有明显的周期性;(3)在Sentinel-1 InSAR观测中,通过固体潮位移相位改正去除了干涉图中的部分低频相位偏差,相比原始干涉图,改正后的解缠相位标准差减小了约29%.本研究对于认识固体潮位移InSAR相位的时空分布特征以及提高星载InSAR广域地表形变监测的准确度与可靠性均具有重要意义. 相似文献
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Most great(M≥8)earthquakes during modern times have occurred in interplate regions or major continental collision zones, such as Sumatra, the Japanese island arc or the San Andreas fault zone. Continental faults slip at a much lower rate than boundary faults, but they also have the potential of generating large earthquakes. For example, the 2008 Wenchuan earthquake with a magnitude of 7.9, the slip rate of seismic fault is less than 3mm/a. They also have the potential to be significantly deadlier than those on plate boundaries because of the long repeat times and lack of preparedness. The January 23rd 1556 Huaxian earthquake in Shaanxi Province, central China, is the deadliest in history with an estimated death toll of ~830 000 from building collapse, land-sliding, famine, and disease. The earthquake occurred in the graben of the Weihe River.
The Weihe Graben in Shaanxi Province has recorded multiple earthquakes in history, whereas most active faults within the graben have a low slip rate over geological times (~1mm/a). The slip rate of faults is an important parameter for assessing the risk of earthquakes and the interval between major earthquake recurrences. In order to obtain the quantitative information of faults slip rate, traditional geological methods or geodetic observation techniques can be used. Interferometric synthetic aperture radar(InSAR), as a modern geodetic observation technology, has the characteristics of all-weather and day-and-night imaging capability, wide spatial coverage, fine resolution, and high measurement accuracy. InSAR offers the potential to measure interseismic slip rates on faults at a resolution of millimetres per year. In this study, we use InSAR data to analyze the present deformation of the Kouzhen-Guanshan, Weihe and North Qinling faults in the central part of the graben.
We collected 32 European Space Agency(ESA's)Envisat ASAR images from descending track 161 between 2003 and 2010, and processed them using ROI_PAC. The precise orbit determination from the Delft Institute for Earth Oriented Space Research(DEOS)was applied to correct for orbital effects. The topographic contribution was simulated and removed using the 90m resolution Shuttle Radar Topography Mission(SRTM)Digital Elevation Model(DEM)from CGIAR-SCI. Each interferogram was downsampled to 64 looks in the range direction (1 280m). Before phase unwrapping, a weighted power spectrum filter was applied to improve the signal-to-noise ratio. The branch-cut method was used for phase unwrapping. Phase unwrapping errors were checked by summing around a closed loop. All the major unwrapping errors were identified and corrected manually. We obtained a total of 98 interferograms with a spatial baseline of smaller than 300m, and selected 33 interferograms whose coherence is well preserved for time-series analysis. The time-series analysis was implemented using the π-RATE software package. It uses the geocoded interferograms from ROI_PAC to create a minimum spanning tree(MST)network, from which the orbital and topographically-correlated atmospheric errors are estimated. The MST network connects all epochs with the most coherent interferograms,including no closed loops of interferograms. The network approach is able to improve the estimation of orbital error by ~9% compared to the independent interferograms approach. The orbital errors are empirically modelled as planar or quadratic ramps. The topographically-correlated atmospheric correction was applied to each interferogram after having corrected for the orbital errors. Following creating a minimum spanning tree network, correcting for orbital and topographically-correlated atmospheric errors, and calculating the covariance matrix, we obtained the 7-year average slip rate of the faults that we are focused on.
Our results show that the faults across the Weihe graben all have a small slip rate of less than 2mm/a. The Kouzhen-Guanshan Fault does not show any evident deformation signal. The Weihe Fault seems to show 1mm/a normal faulting in the satellite line-of-sight direction. In addition, we find ~10mm/a surface subsidence of the Xi'an City between 2003 and 2010. We use the stable Ordos block as a reference to assess the accuracy of our InSAR time-series analysis. Assuming the Ordos block has no internal deformation, we calculated the error of the InSAR rate map to be (-0.1±1)mm/a, indicating that our result is reliable. This paper presents a preliminary result of the present deformation of the Weihe Graben. InSAR is a powerful technique for monitoring active faults on a timescale of tens of years, and can be used for seismic hazard assessment in the future. 相似文献
The Weihe Graben in Shaanxi Province has recorded multiple earthquakes in history, whereas most active faults within the graben have a low slip rate over geological times (~1mm/a). The slip rate of faults is an important parameter for assessing the risk of earthquakes and the interval between major earthquake recurrences. In order to obtain the quantitative information of faults slip rate, traditional geological methods or geodetic observation techniques can be used. Interferometric synthetic aperture radar(InSAR), as a modern geodetic observation technology, has the characteristics of all-weather and day-and-night imaging capability, wide spatial coverage, fine resolution, and high measurement accuracy. InSAR offers the potential to measure interseismic slip rates on faults at a resolution of millimetres per year. In this study, we use InSAR data to analyze the present deformation of the Kouzhen-Guanshan, Weihe and North Qinling faults in the central part of the graben.
We collected 32 European Space Agency(ESA's)Envisat ASAR images from descending track 161 between 2003 and 2010, and processed them using ROI_PAC. The precise orbit determination from the Delft Institute for Earth Oriented Space Research(DEOS)was applied to correct for orbital effects. The topographic contribution was simulated and removed using the 90m resolution Shuttle Radar Topography Mission(SRTM)Digital Elevation Model(DEM)from CGIAR-SCI. Each interferogram was downsampled to 64 looks in the range direction (1 280m). Before phase unwrapping, a weighted power spectrum filter was applied to improve the signal-to-noise ratio. The branch-cut method was used for phase unwrapping. Phase unwrapping errors were checked by summing around a closed loop. All the major unwrapping errors were identified and corrected manually. We obtained a total of 98 interferograms with a spatial baseline of smaller than 300m, and selected 33 interferograms whose coherence is well preserved for time-series analysis. The time-series analysis was implemented using the π-RATE software package. It uses the geocoded interferograms from ROI_PAC to create a minimum spanning tree(MST)network, from which the orbital and topographically-correlated atmospheric errors are estimated. The MST network connects all epochs with the most coherent interferograms,including no closed loops of interferograms. The network approach is able to improve the estimation of orbital error by ~9% compared to the independent interferograms approach. The orbital errors are empirically modelled as planar or quadratic ramps. The topographically-correlated atmospheric correction was applied to each interferogram after having corrected for the orbital errors. Following creating a minimum spanning tree network, correcting for orbital and topographically-correlated atmospheric errors, and calculating the covariance matrix, we obtained the 7-year average slip rate of the faults that we are focused on.
Our results show that the faults across the Weihe graben all have a small slip rate of less than 2mm/a. The Kouzhen-Guanshan Fault does not show any evident deformation signal. The Weihe Fault seems to show 1mm/a normal faulting in the satellite line-of-sight direction. In addition, we find ~10mm/a surface subsidence of the Xi'an City between 2003 and 2010. We use the stable Ordos block as a reference to assess the accuracy of our InSAR time-series analysis. Assuming the Ordos block has no internal deformation, we calculated the error of the InSAR rate map to be (-0.1±1)mm/a, indicating that our result is reliable. This paper presents a preliminary result of the present deformation of the Weihe Graben. InSAR is a powerful technique for monitoring active faults on a timescale of tens of years, and can be used for seismic hazard assessment in the future. 相似文献
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简要介绍了合成孔径雷达干涉测量技术、差分干涉雷达测量技术，并对干涉测量精度进行了简单讨论．以西藏玛尼地区为例，通过三通差分干涉处理，获取了玛尼地震同震形变场.结果表明:形变场长200 km、宽115 km．干涉条纹以北东东向发震断层——玛尔盖茶卡断层为中心分布，且基本与发震断层平行；通过对干涉形变图进行分析，发震断层可分为3段，其中西段长约23 km，中段长约60 km，东段长约26 km，整个发震断层共长110 km；震中附近最大隆起斜距向位移量为162.4 cm，断层西侧最大沉降斜距向位移量为103.6 cm，震中最大地面水平位错为7.96 m． 相似文献
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基于D-InSAR技术的伊朗巴姆地震地表形变监测 总被引：1，自引：1，他引：0
以伊朗巴姆地区为例,对伊朗巴姆地震造成的地表形变进行了差分干涉测量,得到了垂直向的同震三维形变场,并运用GIS三维分析技术对形变场进行了分析。实验结果表明,地震在巴姆城市的东侧造成了较大形变,在西侧也产生了微量形变。巴姆城市北部地块沉降,南部地块隆起。同时在巴姆城市南部可明显看到地震造成的断层。实验结果验证了基于C波段的SAR数据的D-InSAR技术在干燥地区监测地表形变方面的可行性。本文对产生去相关效应的原因进行了解释,认为对于干燥少植被的地区干涉效果较好。并指出,如果能够通过技术进步提高雷达干涉测量的精度并降低观测成本,同时将该技术与GPS、GIS等技术相结合,从而更好地研究形变机理,这将对地质灾害的研究产生重大意义。 相似文献
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D-InSAR技术可以测得地壳垂直形变精度达到mm级,但由于其受空间、时间失相干和大气延迟的限制,导致其在监测地壳长期缓慢形变中的应用受到限制。而PS-InSAR作为D-InSAR技术的创新,在克服时间失相干的同时还可以计算并消除大气影响,使得干涉处理得到的结果更加精确。文中以西秦岭北缘断裂带甘谷地区为实验区,利用从2008年5月至2010年9月共14景ENVISAT ASAR数据,采用PS-InSAR技术对该实验区地壳微小形变进行探测。研究结果得到西秦岭北缘断裂带甘谷地区断裂带南北两盘的相对滑动速率约为5mm/a,点目标的形变速率和形变方向均与西秦岭北缘断裂的左旋运动特征相符,并与其他学者的研究结果有较好的一致性,表明PS-InSAR技术在监测地壳微小形变中具有广阔的应用前景和巨大的发展潜力。 相似文献
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利用Sentinel-1A卫星升降轨道数据和D-InSAR技术获得青海门源2022年1月8日MS6.9地震的同震形变场,并基于弹性半空间位错模型反演其震源参数,利用分布滑动模型确定断层面上的滑动分布。结果表明,2022年1月8日青海门源地震的同震形变场沿NWW-SEE方向分布;断裂带南缘升轨影像和降轨影像最大视距分别为61 cm和62 cm,断裂带北缘升轨影像和降轨影像最大视距地表形变量分别为43 cm和56 cm。InSAR同震形变场断裂尺度模型断层长30 km,宽18 km,最大滑移量3.5 m;断层滑动分布模型表明该地震为左旋走滑地震。结合冷龙岭断裂的运动特征和几何特征,初步确定此次MS6.9地震的发震断裂为冷龙岭断裂 相似文献