共查询到20条相似文献，搜索用时 640 毫秒
1.
提出一种改进的永久散射体PS(Persistent Scatterer)探测方法,首先基于时序SAR影像的振幅信息,利用振幅和振幅离差指数双阈值法获取PS候选点,然后根据干涉相位空间相关性,对所有候选点进行相位稳定性分析,筛选出既满足雷达反射强度高、又符合散射稳定性要求的真实PS点,最后基于所选PS点提取形变信息。选取上海市局部区域作为实验区,以16幅TerraSAR-X(TSX)影像为数据源,进行PS探测和形变信息提取。结果表明,相比于已有的PS探测方法,本文方法能够更准确、可靠地识别出时序SAR影像中的PS点。形变结果显示,研究区域内最大沉降速率为-51mm/a,平均沉降速率为-15.8mm/a,以水准实测数据进行检核,验证了基于改进的PS探测方法进行地表形变信息提取结果的可靠性。 相似文献
2.
本文在改进的永久散射体(PS)探测方法基础上,应用高分辨率永久散射体雷达干涉(PSI)探测上海市地表沉降,并对沉降原因进行了详细分析。实验选取2008年4月至2010年1月间,由德国卫星TerraSAR-X(TSX)所获取的18幅X波段(波长为3.1 cm)高分辨率SAR影像为数据源,进行PS探测、PSI建模、形变提取和分析。实验结果表明,改进的PS探测方法探测出的PS点是合理和可靠的,且高分辨率SAR影像对地面硬目标识别能力较强,显著提高了PS点的密度和覆盖范围。沉降探测结果显示,最大相对沉降速率达30 mm/yr,平均沉降速率为11.5 mm/yr。 相似文献
3.
Polarimetric data is an additional source of information in PSI technique to improve its performance in land subsidence estimation. The combination of polarimetric data and radar interferometry can lead to an increase in coherence and the number of PS pixels. In this paper, we evaluated and compared the dual polarized Sentinel-1A (S1A) and TerraSAR-X (TSX) data to improve the PSInSAR algorithm. The improvement of this research is based on minimizing Amplitude Dispersion Index (ADI) by finding the optimum scattering mechanism to increase the number of PSC and PS pixels. The proposed method was tested using a dataset of 40 dual-pol SAR data (VV/VH) acquired by S1A and 20 dual-pol SAR data (HH/VV) acquired by TSX. The results revealed that using the TSX data, the number of PS pixels increased about 3 times in ESPO method than using the conventional channels, e.g., HH, and VV. This increase in S1A data was about 1.7 times in ESPO method. In addition, we investigated the efficiency of the three polarimetric optimization methods i.e. ESPO, BGSM, and Best for the dual polarized S1A and TSX data. Results showed that the PS density increased about 1.9 times in BGSM and about 1.5 times in Best method in TSX data. However, in S1A data, PS density increased about 1.1 times in BGSM. The Best method was not successful in increasing the PS density using the S1A data. Also, the effectiveness of the method was evaluated in urban and non-urban regions. The experimental results showed that the method was successful in significantly increasing the number of final PS pixels in both regions. 相似文献
4.
永久散射体雷达干涉(PSI)已被广泛应用于城市缓慢沉降监测,但针对显著性地表沉降监测及PSI适用性的探讨较少。本文选取天津市与廊坊市城郊结合部的典型工业化城镇为研究区,分别以2007至2010年间的23幅L波段(23.6 cm)ALOS PALSAR影像和2007至2009年间的23幅C波段(5.6 cm)ENVISAT ASAR影像为数据源,使用基于相位空间相关性分析的PSI方法进行时空沉降提取,并对两个平台的结果进行对比分析和交叉验证。在此基础上,结合长短波SAR对沉降敏感性不同的特征探讨该PSI方法应用于显著沉降解算的可靠性,并结合地质条件及地下水开采信息对实验区沉降的时空分布进行深入分析和解释。研究表明,两平台的沉降结果十分吻合,在沉降漏斗区二者均方根误差(RMSE)为6.5 mm/a;实验区地表沉降呈现出显著的非均匀性,最大沉降速率超过200 mm/a,造成严重沉降的主要原因为地下水的大量开采;证实了PSI方法在显著地表沉降监测方面的有效性和可靠性。 相似文献
5.
常规DInSAR技术中,时空失相关及大气延迟等因素的影响限制了相位解缠结果的精度。永久散射体(PS)InSAR方法间接克服了常规雷达干涉中的时空失相关问题,单独对PS这种高相干目标进行相位解缠可以避免失相关噪声对解缠结果的影响。本文在已有相位解缠方法的基础上,提出基于最小二乘的稀疏PS点相位解缠方法,陈述了相应的建模思想及相关数据处理方法;分别基于模拟数据和真实数据(日本ALOS卫星获取的PALSAR L波段数据)对所提方法进行了实验验证。结果表明,该方法能够有效地对PS数据集进行相位解缠。 相似文献
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7.
Batuhan Osmanoğlu Timothy H. Dixon Shimon Wdowinski Enrique Cabral-Cano Yan Jiang 《International Journal of Applied Earth Observation and Geoinformation》2011
We analyzed 23 satellite SAR (synthetic aperture radar) scenes using Persistent Scatter Interferometry (PSI) to study subsidence in Mexico City associated with groundwater withdrawal. The data were acquired by the Envisat ASAR system between January 2004 and July 2006. The spatial pattern of subsidence and the maximum subsidence rate (300 mm/year) are similar to earlier studies. Comparison to independent GPS data indicates RMS agreement between the two techniques of 6.9 mm/year, about the level expected based on joint data uncertainty. Significant annual variation in the GPS vertical data is not observed, suggesting minimal aquifer recharge during the rainy season, and justifying a simple linear model of phase variation through time for the PSI analysis. 相似文献
8.
PS-InSAR技术地面沉降研究与展望 总被引：2，自引：2，他引：0
近年来,合成孔径雷达差分干涉测量(D-InSAR)技术在许多领域取得了良好的应用成果,但D-In-SAR确受时间失相干因素影响很大,同时大气效应也会影响D-InSAR的测量精度。1999年Ferrettit提出了永久散射体技术(Perm anent Scatterer,PS),它通过识别SAR图像中的永久散射体,消除大气影响,充分利用长基线距的干涉图像对,最大限度地提高数据的利用率,能取得毫米级的地表形变测量精度,因而大大增强了干涉测量的环境适应能力及其精度。本文着重介绍了PS技术原理,对其与D-InSAR相互关系进行了讨论,最后在地面沉降监测等领域开展这项研究潜力进行了展望。 相似文献
9.
Coregistration Based on Three Parts of Two Complex Images and Contoured Windows for Synthetic Aperture Radar Interferometry 总被引：2，自引：0，他引：2
The coregistration of complex image pairs is a very important step in synthetic aperture radar interferometry (InSAR) data processing. This letter proposes a novel coregistration method that only needs three arbitrary parts of the two complex images instead of four parts in the existing coregistration methods. This method constitutes an integrated three-part method for InSAR data processing with our contoured-correlation-interferometry method for phase-image generation. Saving one part transmission makes a significant advantage when processing SAR images on satellites. Furthermore, we demonstrate that, by means of using fringe contoured windows instead of squared windows, the accuracy of the coregistration for both the three-part coregistration method and the existing methods can be improved considerably 相似文献
10.
South-west of Tehran, the capital city of Iran, is subjected to a high deformation rate due to excessive groundwater extractions. Persistent Scatterrer SAR Interferometry (PS-InSAR) technique is used to monitor Tehran’s deformation. Three time series data including two Sentinel-1A (S-1A) spanning from 2014 to 2017, and an ENVISAT-ASAR data stack spanning from 2004 to 2010, are analyzed. The PS-InSAR technique does not perform well on ENVISAT-ASAR due to poor selection of PS points induced by large perpendicular baselines and strong temporal decorrelation of the dataset. In this paper, a novel Iterative PSI method (IPSI) is proposed to increase the PS points which are lost in PS-InSAR technique because of the unsuccessful derivation of the absolute phase value due to an integer ambiguity. The method selects PS points based on simultaneous analysis of their amplitude and phase. Results demonstrate that the density of PSs has been increased by about 4.5 times. Line of Sight (LOS) velocities obtained from both S-1A and ENVISAT-ASAR data analysis are highly compatible with each other, indicating the reliability of the both applied methods. The maximum cumulative displacements are estimated as 39.6 cm and 88.4 cm for Sentinel-1A and ENVISAT-ASAR datasets respectively. Moreover, the subsidence area has grown in the period between the data acquisition time. The methods are successfully validated by subsidence rates obtained from precise leveling and GPS observations. 相似文献
11.
基于时序SAR影像准确识别PS是永久散射体合成孔径雷达干涉(PSI)技术建模及形变信息提取中最为关键的问题之一。本文提出了一种改进的PS探测算法,它是基于时序SAR影像的振幅信息,利用振幅和振幅离差指数双阈值法获取PS候选点,对所有候选点进行相位稳定性分析,筛选出既满足雷达反射强度高、又符合散射稳定性要求的真实PS点,并基于所选PS点提取形变信息。实验结果表明,相比于已有PS探测方法,本文所提出的方法能够更准确、可靠地识别出时序SAR影像中的PS目标,进而提高了PSI形变探测结果的精度和可靠性。 相似文献
12.
Provides a first assessment of a coregistration technique suitable for multiangle fine spatial resolution synthetic aperture radar (SAR) images. The technique is based on crossroad and road junction extraction and matching and exploits recently introduced road extraction routines for SAR data. These features are matched using relational and geometrical analysis. Results are encouraging and show the possibility to exploit multiangle SAR available from future airborne and satellite missions. 相似文献
13.
Methods for classifying land-cover types on the basis of image texture through processing of synthetic-aperture radar (SAR) imagery are described. A combination of statistical characteristics, as well as matrices of conversion probabilities for amplitudes of readings of SAR images, are used in the analysis of texture values. The results of the processing of SIR-C SAR images recorded from aboard the Shuttle spacecraft using these methods are presented for the purpose of classification of forest types. 相似文献
14.
雷达视线受施工机械等的间断遮挡导致部分影像产生相位奇异值，从而造成解缠错误及误差传递，简单的相关影像处理难以识别受遮挡影像。本文提出了改进的基于小波变换的信号奇异性检测方法，通过对地基SAR PS点时序相位特征进行分析，将遮挡影像识别转化为粗差探测问题；由PS点相位序列与影像位置关系，根据测区PS点相位序列的奇异点集合得到受遮挡影像集；最后将受遮挡影像剔除后得到的地基SAR监测结果与精密全站仪、水准与游标卡尺数据进行对比分析。结果表明：本文提出的方法用于受遮挡影像的识别是可行的，解决了地基SAR在实际工程应用中可能存在的影像遮挡带来的测量数据含有粗差的问题，提高了监测区域伪影像检测的效率与准确性。 相似文献
15.
Michael Foumelis 《国际地球制图》2018,33(1):38-52
The combination of ascending and descending persistent scatterers interferometric (PSI) data by means of resampling and/or spatial interpolation, separately for each synthetic aperture radar geometry, is a commonly followed procedure, limited though by the reduced spatial coverage and the introduced uncertainties from multiple rasterization steps. Herein, an alternative approach is proposed for combining different PSI line-of-sight observables in the vector domain, based on the geographic proximity of PS point targets. In the proposed nearest neighbour vector approach all necessary analysis steps are performed by means of attributes transfer and calculations between features geodatabases, prior to any rasterization. By increasing the number of input point vectors during subsequent interpolation, the overall error budget coming from spatial interpolation is being reduced. The advantages of the proposed vector-based approach compared to the commonly used grid-based procedure are being demonstrated using real data. 相似文献
16.
《ISPRS Journal of Photogrammetry and Remote Sensing》2000,55(1):13-33
Relative or absolute elevation extraction from satellite radar data has been an active research topic for more than 20 years. Various investigations have been made on different methods depending on the predominant “fashion” and data availability, leading each time to new developments to improve the capability and the applicability of each method. The paper presents an update of the state-of-the-art of elevation extraction from satellite SAR data. The performance and limitations of four different methods (clinometry, stereoscopy, interferometry and polarimetry) are reviewed, as well as their applicability to different satellite SAR sensors. Their advantages and disadvantages and how they are addressed during the data processing are also analysed. Finally, concluding remarks look at the complementarity aspects of each method to make the best use of the existing and future radar data for elevation extraction. 相似文献
17.
全极化SAR获取的信息量远多于传统SAR,但信息量的增加并不能确保分类精度的提高,如何有效进行特征选择至关重要。针对自适应特征选择问题,提出一种顾及分类器参数的特征选择和分类方法。该方法以支持向量数为评估依据,结合遗传算法进行特征选择,并同时对分类器参数进行寻优;最后利用优选的特征集和模型参数进行分类。为验证算法的有效性,利用两组全极化数据进行了监督分类实验。实验结果表明,提出方法降低了SVM分类器对自身参数的敏感性,而且能在较少特征个数下具备良好的泛化性能,分类精度优于未经过特征选择和参数优化的方法。 相似文献
18.
Fulong Chen Nicola Masini Jie Liu Jiangbin You Rosa Lasaponara 《International Journal of Digital Earth》2016,9(12):1224-1241
Synthetic Aperture Radar (SAR) remote sensing is increasingly favoured in archaeological applications. However, the effectiveness of this technology for archaeological prospection has so far not been fully assessed. In this study, an integrated single-date and multi-temporal SAR data-processing chain was proposed to sharpen archaeological signs and hence their detection and monitoring. In total, 14 scenes of X-band Cosmo-SkyMed, C-band Sentinel-1 and L-band PALSAR data covering the Western Regions of the Silk Road Corridor in China were employed for two important archaeological sites including the Yumen Frontier Pass with emerging archaeological traces and Niya ruins with subsurface remains. The results pointed out that single-date satellite radar data were useful for the identification of subsurface traces buried under desert in the landscape-scale, whereas for the identification of emerging monuments, Sentinel-1 was limited by its lower spatial resolution compared to TerraSAR and PALSAR data. Multi-date products, such as interferometric coherence, the averaged radar signatures and RGB multi-temporal composites, were effective to sharpen archaeological traces as well as for change detection in Yumen Frontier Pass. This study presents a pilot assessment of satellite SAR data for the analysis and monitoring of archaeological features in the predominantly arid-sandy environmental characteristic of investigated sites. 相似文献
19.
Jinshan Ding Zhenhua Zhang Mengdao Xing Zheng Bao 《Geoscience and Remote Sensing Letters, IEEE》2008,5(3):392-395
20.
The reconstruction of digital surface models (DSMs) of urban areas from interferometric synthetic aperture radar (SAR) data is a challenging task. In particular the SAR inherent layover and shadowing effects need to be coped with by sophisticated processing strategies. In this paper, a maximum-likelihood estimation procedure for the reconstruction of DSMs from multi-aspect multi-baseline InSAR imagery is proposed. In this framework, redundant as well as contradicting observations are exploited in a statistically optimal way. The presented method, which is especially suited for single-pass SAR interferometers, is examined using test data consisting of experimental airborne millimeterwave SAR imagery. The achievable accuracy is evaluated by comparison to LiDAR-derived reference data. It is shown that the proposed estimation procedure performs better than a comparable non-statistical reconstruction method. 相似文献