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1.
极具潜力的空间对地观测新技术——合成孔径雷达干涉   总被引:33,自引:0,他引:33  
“合成孔径雷达干涉(InSAR)”是近十年发展起来的空间对地观测遥感新技术。它具有从覆盖同一地区的星载(或机载)合成孔径雷达复数图像对提取干涉相位图,借助于雷达成像时的姿态数据重建地表三维模型(即数字高程模型)的巨大潜力。尤其是基于多幅雷达复数图像处理的差分干涉技术(D-InSAR)可以用于监测地表形变,精度可达厘米级甚至更高,其监测空间分辨率是前所未有的。介绍了InSAR和D-InSAR的基本原理,对影响干涉结果的一些重要因素做了分析,重点回顾和展望了差分干涉技术在与地表形变有关的地震监测和震后形变测量、地面下沉和山体滑坡、火山运动监测等方面应用的现状和前景。  相似文献   

2.
用InSAR技术提取数字高程模型的研究   总被引:2,自引:1,他引:2  
合成孔径雷达干涉测量(InSAR,Synthetic Aperture Radar)是一种获取地面数字高程模型(DEM)和探测地面微小形变的新技术。这里概述了干涉测量的发展历史,介绍了干涉测量的基本原理,并利用青藏高原库塞湖地区的数据对干涉测量获得地面数字高程模型进行了详细的阐述,最后对生成的地面数字高程模型进行结果分析。  相似文献   

3.
在美国直接受下陷影响地区达45个,受灾面积超过17000平方英里,每年相关经济损失约为125万美元。导致下陷的主要原因有含水层系统挤压、有机土壤排水、地下采矿、自然挤压、污水池、冻土融化等(国家调查委员会,1991)。一个强大的映射成图工具(InSAR)对于评估和缓解下陷方面比较有效。InSAR能够以惊人的精度监测地表微小形变。InSAR所形成的干涉图增强了我们监控和处理由于含水层系统挤压引起的下陷,也展现了人类控制自然物理过程的新视野。干涉合成孔径雷达(InSAR)是一种新型的用雷达信号监测地表微小形变的工具,其反映的空间细节水平非常惊人,测量结果精度很高。美国地质调查局及其他一些单位正在利用InSAR成图和监控由于含水层系压造成的。  相似文献   

4.
<正>合成孔径雷达干涉测量(InSAR)技术因其具有高分辨率、高精度等特点,已广泛用于地震、火山、地面沉降等地表形变的监测中。然而,InSAR技术仅能获取雷达视线方向的一维形变信息,仅依靠单一轨道的SAR数据不能完全、准确地反映监测区的地表形变特征,这一缺陷大大限制了InSAR技术在地表形变监测中的推广应用。随着Envisat ASAR、ALOS PALSAR、Radarsat-2、COSMO-SkyMed和TerraSAR-X等雷达卫星数据的不断获取,在同一  相似文献   

5.
合成孔径雷达干涉测量(interferometric synthetic aperture radar,简称InSAR)是获取地表形变的重要手段,由于InSAR数据获取的限制和数据处理中产生的精度误差等问题,在地灾隐患识别方面的工作还需要联合地质灾害本身进行分析.为此提出了一种基于InSAR技术与研究区孕灾背景指标相结...  相似文献   

6.
INSAR技术在北京来广营地区地面沉降监测中的应用   总被引:1,自引:0,他引:1  
王颖 《城市地质》2011,6(4):57-60
北京市平原地区地面沉降危害日益显著,合成孔径雷达干涉测量(InSAR)具有快速、高精度、周期短等优势,可为城市地面沉降监测提供有效的技术手段。本文选用ENVISAT-1卫星SAR数据监测研究2004-2005年北京来广营地区地面沉降,利用InSAR差分技术得到该地区地面沉降监测结果。  相似文献   

7.
InSAR(合成孔径干涉雷达测量)是一种新型对地观测技术,由于其高精度、大区域、可穿透云雾、全天候、全天时的工作特性,在数字高程模型(DEM)提取以及地表形变监测方面有着独特的优势.在InSAR图像处理的过程中,相位解缠是至关重要的一步,相位解缠效果的好坏直接影响到高程图的精度.本文利用ASAR数据,在ROI_PAC软件下进行处理,对DEM提取流程进行简要的分析.ROI_PAC软件处理InSAR数据所应用的相位解缠算法是最经典的路径跟踪法——枝切法.对于该算法本文进行了详细的分析探讨,并针对算法中残差点搜索的过程提出了一种新的改进算法思想.  相似文献   

8.
该文详细论述与分析了合成孔径雷达干涉测量(InSAR)的干涉几何特征及InSAR影像之间的相关性特征,着重阐述并分析了影响其地学监测方面的数据质量等相干技术问题,就InSAR开展上海城市地面沉降研究提出了基本思路,对InSAR城市遥感应用的潜在意义进行了分析和讨论。  相似文献   

9.
目前合成孔径雷达干涉(interfermoetic SAR,InSAR)理论与技术一直处于快速发展态势,在地质灾害隐患识别方面已有阶段性的进展,但是为了提高识别的效率与准确度还需进一步的研究。因此提出一种联合时序InSAR(Interfermoetic SAR)技术和滑坡灾害易发性的方法对云阳县进行滑坡灾害早期识别。该方法通过小基线集干涉测量(Small Baseline Subset InSAR, SBAS-InSAR)技术获得该地区地表形变信息,再结合通过信息量模型以地貌类型、土地利用类型、断层距离、高程、工程地质岩组、坡度、坡向、曲率与河流距离9个评价因子作为信息量值获得的滑坡灾害易发性区划与谷歌影像分层次进行潜在滑坡灾害的识别。然后对识别结果进行验证,研究表明了该种方法在此地区应用的可行性,且研究成果为地质灾害进一步的调查提供了参考与技术支持。  相似文献   

10.
基于合成孔径雷达干涉测量技术的地面沉降研究综述   总被引:2,自引:0,他引:2  
综述了合成孔径雷达干涉测量(InSAR)技术的研究现状及其在监测地面沉降方面的优势和缺陷.与传统监测方法相比,InSAR技术在地面沉降监测方面主要具有全天候、大范围、高分辨率、高精度等优势,但在实际应用中则会产生去相关问题.探讨了利用该技术监测地面沉降的发展方向,认为应将InSAR与GPS及传统的水准测量等方法结合使用,合理利用各技术之间的互补性.  相似文献   

11.
Heavy mining of Jurassic and Carboniferous horizontal coal seams in the Datong coalfield has seriously affected the local geological environment, which is mainly manifested by such geohazards as soil avalanches, landslides, mudflows, surface subsidence, surface cracks, surface solid waste accumulation and surface deformation. More seriously, coal mining causes groundwater to leak. Overpumping of groundwater has resulted in substantial land subsidence of the urban area in Datong City. Based on the previous geo-environmental investigation in the work area, the authors used radar remote sensing techniques such as InSAR (synthetic aperture radar interferometry) and D-InSAR (differential synthetic aperture radar interferometry), supplemented by the optical remote sensing method, for geo-environmental investigation to ascertain the geo-environmental background of the Datong Jurassic and Carboniferous-Permian coalfield and evaluate the effects of the geohazards, thus providing a basis for the geo-environmental protection, geohazard control and prevention, land improvement and optimization of the human environment. In this study 8 cog-nominal ERS-1/2 SAR data frames during 1992 to 2003 were used, but the following processing was made: (1) the multitemporal SAR magnitude images were used to interpret the geological structure, vegetation, microgeomorphology and drainage system; (2) the multi-temporal InSAR coherent images were used to make a classification of surface features and evaluate the coherence change due to coal mining; and (3) the multi-temporal cog-nominal SAR images were used to complete D-InSAR processing to remove the information of differential deformation areas (sites). In the end, a ten-year time series of differential interferograms were obtained using the multi-temporal cog-nominal SAR images. In the tests, 84 deformed areas (sites) were obtained, belonging to those in 1993-1996, 1996-1997, 1997-1998, 1998-2001, 1998-2002 and 2001-2003 respectively. Of the 84 areas, 44 are m  相似文献   

12.
作为大地测量的一种新兴空间技术,合成孔径雷达干涉(synthetic aperture radar interferometry, InSAR)具有全天时、高精度、大范围和速度快的优点,逐渐被应用于多年冻土区地表形变监测中。通过综述多年冻土形变原理及InSAR监测多年冻土形变的应用实例,研究表明:在气候变暖的背景下,多年冻土区地表年际形变以下沉为主,多年冻土上限附近地下冰含量的大小是影响年际形变量的主要因素;活动层内土壤含水量影响着地表季节形变量的大小,不同类型多年冻土区的地表年际形变量和季节形变量存在着较大的差异。研究还表明,不同波长的SAR产品在不同类型多年冻土区的适用性不同,下垫面特征对利用InSAR获取地表形变量有较大影响,L波段的SAR数据在植被覆盖度较好的区域有更好的效果。由于InSAR的失相干问题,加之目前还缺少长时间、多类型、高频率的实测形变结果作为验证和标校数据,获取准确且连续的大范围形变数据较为困难。针对目前寒区研究需求,布设野外长期观测站点,建立适用于不同多年冻土区的地表形变反演算法,构建具有较高精度和较高时空分辨率的地表形变数据集具有重要的实践和科学意义。  相似文献   

13.
合成孔径雷达干涉测量技术(SAR)经过10多年的发展,现已广泛的应用于地球学科的各个领域.目前主流的GAMMA解算软件,采用二轨差分的方法,对实验区的SAR数据进行配准、滤波、去平地效应、相位解缠、差分等处理,最后得到垂直形变图,实现了地表形变的监测.本次研究SAR数据为欧空局的ERS-2卫星数据,DEM分辨率为30 m,采用最小费用流法解缠,得到于雷达视线方向上的形变量,再通过计算与转换,生成垂直方向上的形变图.结果表明,研究区城市中及其周边发现明显的沉降中心,在山区地带基本没有沉降.  相似文献   

14.
This paper investigates surface elevation changes that occurred during 1996–2004 in the Jharia coalfield through the digital elevation model (DEM) generated using synthetic aperture radar interferometry (InSAR) using ERS-1/2 (European Remote Sensing Satellite) tandem and RADARSAT-1 data. The comparison of elevation values derived from the InSAR DEM and topographic height data shows a bias of 23.08 m with root-mean-square error of ±2.31 m (5.8 %). The accuracy of the DEM was investigated by comparing the elevation profiles with the digitized elevation contour data at four different locations. The profile comparison shows a mean bias of 22.68 m. Local topography shows changes in elevation up to ±40.00 m due to mining activities on the 8-year time period. The results of InSAR-derived heights and topographic heights were comparable and well-matched except at a few locations where topographic data were unavailable. DEM generated using InSAR due to its high spatial details is ideal for the detection and estimation of surface elevation changes in mining areas.  相似文献   

15.
Interferometric synthetic aperture radar (InSAR) analysis is a radar technique for generating large-area maps of ground deformation using differences in the phase of microwaves returning to a satellite. In recent years, high-resolution SAR sensors have been developed that enable small-scale slope deformation to be detected, such as the partial block movement of a landslide. The L-band SAR (PALSAR-2) is mounted on Advanced Land Observing Satellite-2 (ALOS-2), which was launched on 24 Mar. 2014. Its main improvements compared with ALOS are enhanced resolution of as high as 3 m with a high-frequency recurrence period (14 days). Owing to its high resolution and the use of the L-band, PALSAR-2 can obtain reflective data passing through a tree canopy surface, unlike the other synthetic aperture radars. Therefore, the coherence of InSAR in mountainous forest areas is less likely to decrease, making it advantageous for the extraction of slope movement. In this study, to verify the accuracy of InSAR analysis using PALSAR-2 data, we compared the results of InSAR analysis and the measurement of the displacement in a landslide by global navigation satellite system (GNSS) observation. It was found that the average difference between the displacements obtained by InSAR analysis and the field measurements by GNSS was only 15.1 mm in the slant range direction, indicating the high accuracy of InSAR analysis. Many of the areas detected by InSAR analysis corresponded to the locations of surface changes due to landslide activity. Additionally, in the areas detected by InSAR analysis using multiple datasets, the ground changes due to landslide movement were confirmed by site investigation.  相似文献   

16.
This paper is addressed to readers without advanced knowledge of remote sensing. It illustrates some current and potential uses of satellite Synthetic Aperture Radar interferometry (InSAR) for landslide assessment. Data acquired by SAR systems can provide 3D terrain models and be used to assist in regional scale investigations, e.g. aimed at evaluation of susceptibility of slopes to failure. Under favourable environmental conditions, the innovative Permanent Scatterers (PS) technique, which overcomes several limitations of conventional SAR differential interferometry (DInSAR) applications in landslide studies, is suitable for monitoring slope deformations with millimetric precision. The PS technique combines the wide-area coverage typical of satellite imagery with the capability of providing displacement data relative to individual image pixels. With the currently available radar satellites, however, only very slow ground surface displacements can be reliably detected and measured. The presented case study of a landslide from the Liechtenstein Alps indicates that the most attractive and reliable contribution provided by this remote sensing technique lies in the possibility of (i.) wide-area qualitative distinction between stable and unstable areas and (ii.) qualitative (relative) hazard zonation of large, slow landslides based on the identification of segments characterised by different movement rates. Since only the radar line of sight projection of the displacements can be detected, a quantitative exploitation of the PS data is possible only where sufficient ground truth is available. In site specific or single landslide investigations the PS data can represent a very useful complementary data source with respect to the information acquired through ground based observations and in situ surveying. However, the difficulties associated with the feasibility assessments of the applicability of SAR data to local scale problems, as well as with the interpretation of PS results, require a close collaboration between landslide experts and specialists in advanced processing of radar satellite data. The interpretation of the exact geotechnical significance of small, radar sensed ground surface deformations is challenging, especially where ground truth is lacking. Although any ground deformation is potentially of interest to an engineering geologist, detection of movements in both vertical and horizontal directions is needed in the case of landslides to evaluate slope failure mechanisms. With their high radar viewing angles, however, the current space-borne systems can detect only a fraction of the horizontal component of movement. It is expected that the upcoming SAR dedicated missions with new sensors and different acquisition geometries, combined with the rapid developments in the field of advanced radar data processing, will allow a full 3D reconstruction of deformation data and help to further reduce the current limitations of the PS and similar DInSAR approaches.  相似文献   

17.
The application of satellite differential synthetic aperture radar (SAR) interferometry, principally coherent (InSAR) and to a lesser extent, persistent-scatterer (PSI) techniques to hydrogeologic studies has improved capabilities to map, monitor, analyze, and simulate groundwater flow, aquifer-system compaction and land subsidence. A number of investigations over the previous decade show how the spatially detailed images of ground displacements measured with InSAR have advanced hydrogeologic understanding, especially when a time series of images is used in conjunction with histories of changes in water levels and management practices. Important advances include: (1) identifying structural or lithostratigraphic boundaries (e.g. faults or transitional facies) of groundwater flow and deformation; (2) defining the material and hydraulic heterogeneity of deforming aquifer-systems; (3) estimating system properties (e.g. storage coefficients and hydraulic conductivities); and (4) constraining numerical models of groundwater flow, aquifer-system compaction, and land subsidence. As a component of an integrated approach to hydrogeologic monitoring and characterization of unconsolidated alluvial groundwater basins differential SAR interferometry contributes unique information that can facilitate improved management of groundwater resources. Future satellite SAR missions specifically designed for differential interferometry will enhance these contributions.  相似文献   

18.
In recent years SAR interferometry has become a widely used technique for measuring altitude and displacement of the surface of the earth. Both these capabilities are highly relevant for landslide susceptibility studies. Although there are many problems that make the use of SAR interferometry less suitable for landslide inventory mapping, it’s use in landslide monitoring and in the generation of input maps for landslide susceptibility assessment looks very promising. The present work attempts to evaluate the usefulness and limitations of this technique based on a case study in the Swiss Alps. Input maps were generated from ERS repeat pass data using SAR interferometry. A land cover map has been generated by image classification of multi-temporal SAR intensity images. An InSAR DEM was generated and a number of maps were derived from it, such as slope-, aspect, altitude- and slope form classes. These maps were used to generate landslide and rockfall susceptibility maps, which give fairly well acceptable results. However, a comparison of the InSAR DEM with the conventional Swisstopo DEM, indicated significant errors in the absolute height and slope angles derived from InSAR, especially along the ridges and in the valleys. These errors are caused by low coherence mostly due to layover and shadow effects. Visual comparison of stereo images created from hillshading maps and corresponding DEMs demonstrate that a considerable amount of topographic details have been lost in the InSAR-derived DEM. It is concluded that InSAR derived input maps are not ideal for landslide susceptibility assessment, but could be used if more accurate data is lacking.  相似文献   

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