共查询到20条相似文献，搜索用时 31 毫秒
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《地理信息系统科学与遥感》2013,50(2):208-220
The monitoring of slope instability requires detailed observations of mass movements, which generally cannot be obtained by geodetic methods or global positioning systems (GPS). Differential synthetic aperture radar (SAR) interferometry has proven to be an effective way of measuring land deformation with millimeter accuracy over wide areas. Using data from the newly launched L-band ALOS PALSAR interferometer and the multi-baseline differential SAR interferometry technique, slope instability in Hong Kong was analyzed by means of measured surface displacement along look vectors. Owing to its enhanced vegetation penetration, less temporal decorrelation enabled the L-band data to improve spaceborne radar sensor land-surface deformation measurements. The results were validated by ENVISAT ASAR-derived outcomes and other ground survey data. 相似文献
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本文针对2010年4月14日玉树地震引起的地表形变,使用日本ALOS卫星PALSAR L波段雷达影像数据,应用两轨雷达差分干涉(DInSAR)处理得到了以玉树为中心11 000km2范围内的同震形变场,空间分辨率为8m,并在此基础上对玉树地震的震源机制和发震机理进行了分析。研究结果表明L波段雷达数据适合在地形起伏较大的地区进行DInSAR形变探测。该同震形变场信息可为玉树地震的同震形变反演提供参考数据。该研究进一步证实DInSAR技术在大规模地表形变探测和地学研究领域具有广阔的应用前景。 相似文献
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Vertical deformation estimation can be a significant tool in preventing geological hazards and managing environment impacts of underground mining. Common ground surface vertical deformation calculations are challenged by difficult data collection and dependence on prior knowledge. SVD (singular value decomposition) method was applied to estimate ground surface vertical deformation from single pair SAR (synthetic aperture radar) data in a mining region. During the study, LOS (line of sight) and azimuth displacement was obtained using two pass D-InSAR (differential interferometry synthetic aperture radar) and MAI (multi-aperture radar interferometry) technology, respectively. Two adjustment equations were composed using the imaging geometry of D-InSAR and MAI. The singular value decomposition theorem was used to acquire M-P (Moore-Penrose) generalized inverse of the rank deficiency coefficient matrix. From this, the optimal approximation solution of unknown parameters was calculated using weighted least squares. A working panel in the Datong mining area, Shanxi province, China, was selected to verify the SVD approach using the two ascending Sentinel-1A data. The accuracy of vertical deformation estimated by SVD approach is reliable. The RMSE (root mean square error) of vertical deformation is 2.64 mm (along upright profile) and 4.95 mm (along horizontal profile). These results suggest that the SVD approach will complement widely used vertical ground surface deformation calculations. Further study is needed to validate the method from other deformation scenarios from landslides, groundwater loss, earthquakes, underground mining, and glacier movement. 相似文献
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合成孔径高度计的海面回波仿真 总被引：1，自引：0，他引：1
本文首先采用经验海浪谱仿真了三维海面,进而在此基础上根据镜面反射理论计算了海面小面元散射系数。然后根据雷达方程和合成孔径高度计的合成孔径处理计算了海面回波信号的矩阵,以便给出最终的功率回波。在目前国内外缺少相应试验数据的条件下,验证了合成孔径高度计工作方式的有效性,经验证其回波模型基本正确。同时,为了与传统高度计比较,给出了传统高度计在相同参数下的回波仿真结果。文章还通过展示合成孔径高度计在同种波高、不同涌浪和风浪方向情况下的回波,说明波浪方向也会影响合成孔径高度计回波。 相似文献
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地铁建设会引发城市地表形变灾害,而传统的合成孔径雷达差分干涉测量（D-InSAR）难以实现城市地铁工程区域的精细测量。本文利用TerraSAR-X高分辨率数据,采用PS-InSAR和SBAS-InSAR方法对徐州地铁1号线东部工程场地进行了形变监测,获取了该区域2016年6月15日-2016年9月11日期间的形变时序图。通过与人工角反射器布设点的水准测量数据对比分析,发现利用两种时序InSAR测量方法得到的地表形变结果与水准测量结果非常一致,形变误差均在1 mm以内;而SBAS-InSAR探测地表形变的敏感性低于PS-InSAR。结果表明,利用高分辨率SAR影像监测城市地铁形变具有亚毫米级的测量精度和米级的定位能力,同时证明了时序InSAR分析技术在城市地铁工程形变监测应用中的广阔前景。 相似文献
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Md Soyeb Alam Dheeraj Kumar R. S. Chatterjee Vijay Upreti 《Journal of the Indian Society of Remote Sensing》2018,46(10):1569-1580
Differential interferometric synthetic aperture radar (DInSAR) is a novel remote sensing technique to measure earth surface deformation. It is capable of obtaining dense information related to the deformation of a large area efficiently, economically and effectively. Therefore, DInSAR is a promising technology for monitoring the earth surface deformation related to some natural hazardous events, such as earthquake, volcano eruption, land subsidence, landslide. In present study, Conventional DInSAR technique have been applied to a mineral rich zone, coming under the Khetri copper belt, a part of Northern Aravali range of hillocks in India, predominant with mining activities since late 1960’s to address the possibility of deformation phenomena due to hard rock underground metal mining. Four interferometric SAR data sets of Radarsat-2 was used for the study area to address the subsidence/uplift phenomena. Further, results obtained from conventional DInSAR technique using Radarsat-2 data sets compared with results obtained from ground based observation technique for its validity. In both the techniques, deformation results obtained in terms of average subsidence rate in mm (quarterly basis) of points under study within mining zone of Mine-A has well agreed to each other. Further, it has been observed that average subsidence rate in mm (quarterly basis) obtained from space based observation and ground based observation are 5.6 and 6.67, respectively over the points under study in mining zone of Mine-A. 相似文献
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当前矿区合成孔径雷达差分干涉测量(D-InSAR)监测研究大多局限于以地表移动为对象,求取其他形变指标通常仍需野外测量。针对这一不足,构建出一种提取地表移动变形(surface movement and deformation,SMD)面域信息的模型——SMD模型。模型可求解的量有:①地表沿任意方向的倾斜、曲率,地表倾斜、曲率最大值与其所沿方向;②水平或近水平煤层开采下,矿区地表沿任意方向的水平移动、水平变形,地表水平移动、水平变形最大值和其所沿方向。SMD模型在垂直形变图的基础上,按照方向导数原理计算地表倾斜和曲率;地表水平移动和水平变形则根据开采沉陷先验规律计算。模拟试验显示,该模型可以较高精度获取地表移动变形值。淮北矿区某矿进行了充填开采,应用SMD模型结合时序InSAR分析该矿地表形变时空演化过程,以及充填开采的减沉减变效果,分析认为注浆活动可以有效控制地表形变。日平均注浆量、工作面推进距离与最大下沉速度之间的关系可以用多元线性回归模型来描述。SMD模型可用于分析区域地表形变综合情况,为范围评估开采沉陷对建构筑物的影响提供有力依据。 相似文献
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利用哨兵（Sentinel）-1A卫星升、降轨影像,在地震位错模型约束下获取了2017年九寨沟Mw 6.5地震的高质量三维形变场。首先,利用合成孔径雷达干涉测量技术（interferometric synthetic aperture radar,InSAR）提取九寨沟地震升、降轨同震形变场;然后,通过“两步法”反演获取该地震发震断层的几何参数和分布式滑动模型,以此为约束,采用方差分量估计算法联合解算九寨沟地震三维形变场。结果表明,九寨沟地震同震三维形变场以水平位移为主,垂向形变较弱;南北向形变呈拉张趋势,断层上盘向南、下盘向北滑动,最大位移分别为－19.81 cm和14.38 cm;东西向形变不对称性明显,断层上盘西北部向东水平运动,最大位移为18.37 cm,下盘东南部向西运动,最大位移不足8 cm。将南北、东西向形变与6个全球导航卫星系统（global navigation satellite system,GNSS）台站观测数据进行比较,两者一致性较好且均方根误差较小,分别为1.44 cm和1.77 cm,表明联合升、降轨InSAR观测和地震位错模型约束构建同震三维形变场方法具有较高可行性,显著降低了大地测量数据不足、InSAR观测对南北向形变不敏感等问题的影响。 相似文献
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干涉雷达时间序列分析方法在地面沉降监测中的应用 总被引：1，自引：0，他引：1
地面沉降已经成为全球性问题，传统的大地测量技术在日益严重的大范围地面沉降监测方面越来越显得难以胜任，新兴的
雷达干涉测量技术正好提供了一种大覆盖、高空间和高时间分辨率的地面沉降监测手段。本文以天津地区为实验区，介绍并实现了
利用PS点的InSAR时间序列分析方法，取得了较好的实验结果。 相似文献
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This paper reviews the advanced differential interferometry synthetic aperture radar (A-DInSAR) techniques, with two major components in focus. First is the basic concepts, synthetic aperture radar (SAR) data sources and the different algorithms documented in the literature, primarily focusing on persistent scatterers. In the second part, the techniques are compared in order to establish more linkage in terms of the variability of their applications, strength and validation of the interpreted results. Also, current issues in sensor and algorithm development are discussed. The study identified six existing A-DInSAR algorithms used for monitoring various deformation types. Generally, reports of their performance indicate that all the techniques are capable of measuring deformation phenomena at varying spatial resolution with high level of accuracy. However, their usability in suburban and vegetated areas yields poor results, compared to urbanized areas, due to inadequate permanent features that could provide sufficient coherent point targets. Meanwhile, there is continuous development in sensors and algorithms to expand the applicability domain of the technology for a wide range of deformable surfaces and displacement patterns with higher precision. On the sensor side, most of the latest SAR sensors employ longer wavelength (X and P bands) to increase the penetrating power of the signal and two other sensors (ALOS-2 PALSA-2 and SENTINEL-1) are scheduled to be launched in 2013. Researchers are investigating the possibility of using single-pass sensors with different look angles for SAR data collection. With these, it is expected that more data will be available for various applications. Algorithms such as corner reflector interferometry SAR, along track interferometry, liqui-InSAR, and squeeSAR are emerging to increase reliable estimation of deformation from different surfaces. 相似文献
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以四川省茂县、安县地区的ALOS PALSAR L波段雷达影像为数据源,在对地形复杂区的配准、解缠等算法研究的基础上,结合SAR特有的成像几何结构,对两幅SAR图像进行快速自动配准,配准误差小于0.2个像元;在去除平地引起的干涉相位变化后,运用MCF对缠绕相位进行解缠,在此基础上提取研究区的数字高程模型(DEM),分析发现精度受多种因素影响,其中波长较长的L波段数据比波长较短的时间相关性好,此外为消除大气效应,采用改进的相位累积法去除大气的影响,在一定程度上提高DEM精度。其误差范围在±10m左右,对快速提取地形信息具有一定的借鉴意义。 相似文献
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A survey of remote sensing-based aboveground biomass estimation methods in forest ecosystems 总被引：7，自引：0，他引：7
Dengsheng Lu Qi Chen Guangxing Wang Lijuan Liu Guiying Li Emilio Moran 《International Journal of Digital Earth》2016,9(1):63-105
Remote sensing-based methods of aboveground biomass (AGB) estimation in forest ecosystems have gained increased attention, and substantial research has been conducted in the past three decades. This paper provides a survey of current biomass estimation methods using remote sensing data and discusses four critical issues – collection of field-based biomass reference data, extraction and selection of suitable variables from remote sensing data, identification of proper algorithms to develop biomass estimation models, and uncertainty analysis to refine the estimation procedure. Additionally, we discuss the impacts of scales on biomass estimation performance and describe a general biomass estimation procedure. Although optical sensor and radar data have been primary sources for AGB estimation, data saturation is an important factor resulting in estimation uncertainty. LIght Detection and Ranging (lidar) can remove data saturation, but limited availability of lidar data prevents its extensive application. This literature survey has indicated the limitations of using single-sensor data for biomass estimation and the importance of integrating multi-sensor/scale remote sensing data to produce accurate estimates over large areas. More research is needed to extract a vertical vegetation structure (e.g. canopy height) from interferometry synthetic aperture radar (InSAR) or optical stereo images to incorporate it into horizontal structures (e.g. canopy cover) in biomass estimation modeling. 相似文献
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Excessive groundwater extraction has caused land subsidence in a large rural area located southwest of Tehran, Iran. We used radar images to estimate the temporal and spatial variation in the magnitude of the subsidence. Due to the large perpendicular baselines and rapid temporal decorrelation of the available data, the application of conventional synthetic aperture radar interferometry (InSAR) to monitor the deformation was not possible. Instead, we applied a recently developed Persistent Scatterer InSAR (PSI) method but found that displacements were underestimated in some areas due to high deformation rates that cause temporal aliasing of the signal. We therefore developed a method that combines conventional InSAR and PSI to estimate the high deformation rates in the southwestern Tehran Basin. We used rates estimated from conventional small temporal baseline interferograms to reduce the likelihood of aliasing and then applied PSI to the residual phase. The method was applied to descending and ascending ENVISAT ASAR images spanning from 2003 to 2009. Mean line-of-sight velocities obtained from both orientations that were further decomposed into horizontal and vertical deformation components were highly compatible with each other, indicating the high performance of the applied method. The mean precision of the estimated vertical component is 2.5 mm/yr. We validated our results using measurements from a continuous GPS station located in one of the subsiding areas. The results also compare favourably with levelling data acquired over a different time interval. Finally, we compared the estimated displacements to hydraulic head variations and geologic profiles at several piezometric wells. We found that the geology is the most important factor controlling the subsidence rate in the southwestern Tehran Basin, regardless of the water level decline. 相似文献
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将卫星雷达遥感应用于滑坡灾害的探测与监测，不仅可以从空间尺度上大范围捕捉到滑坡信号，而且可以从时间尺度上以较长周期追踪滑坡的运动状态。但是，卫星雷达遥感本身的局限性和滑坡所处的复杂地形环境使这一应用面临一些挑战。对卫星雷达遥感技术的4个主要挑战进行了总结与分析，同时给出了相应的解决方案:①通过提高卫星雷达影像的空间、时间分辨率，使用较长波段雷达信号或采用增强型时间序列分析技术，可降低密集植被覆盖对相干性的影响。另外，采用像素点偏移量追踪或距离向分频干涉测量方法，可克服传统干涉测量中大梯度形变引起的相位失相干。②大气延迟对卫星遥感的影响较大，尤其是地处山区的滑坡探测和监测，利用通用型卫星雷达大气改正系统可显著减弱干涉影像的大气信号并进一步简化时间序列分析，提高缓慢运动滑坡的探测和监测质量。③对于中等分辨率的雷达影像而言，利用数字高程模型可提前量化分析雷达几何畸变（如叠掩、阴影等）引发的滑坡探测监测的适用性；而对于高分辨率的雷达影像而言，利用机器学习方法无需外部高分辨率数字高程模型即可精确识别雷达影像的阴影和叠掩区并进行掩膜，从而大幅度提高数据处理效率。④针对高坡度地区残余的地形相位引起的解缠误差，可通过基线线性组合的方法予以减弱。此外，提出了一个基于多源对地观测的滑坡探测/监测系统框架，综合卫星雷达遥感与其他对地观测数据（如地基雷达、激光雷达、全球导航定位系统），搭建了一个自动化滑坡探测与监测系统。该研究旨在阐明卫星雷达遥感的优缺点，进一步深化其在滑坡灾害监测方面的应用和推广，引出未来侧重发展方向的思考与探讨。 相似文献
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干涉合成孔径雷达是一项能够对地表变形进行测量的遥感技术,在一个巨大区域内,它的变形测量精度可达亚厘米级,而其空间分辨率则在数十米以内。本文回顾了InSAR技术的基本理论,阐明了它的工作原理,并对应用InSAR技术进行地表变形测量的相关问题进行了讨论。 相似文献
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Accurate estimation of correlation in InSAR observations 总被引：4，自引：0，他引：4
Interferometric synthetic aperture radar (InSAR) correlation, a measure of the similarity of two radar echoes, provides a quantitative measure of surface and subsurface scattering properties and hence surface composition and structure. Correlation is observed by comparing the radar return across several nearby radar image pixels, but estimates of correlation are biased by finite data sample size and any underlying interferometer fringe pattern. We present a method for correcting bias in InSAR correlation measurements resulting in significantly more accurate estimates, so that inverse models of surface properties are more useful. We demonstrate the value of the approach using data collected over Antarctica by the Radarsat spacecraft. 相似文献