| 基于子带干涉测量技术的巴基斯坦地震形变获取研究 |
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| 引用本文： | 庾露,单新建,宋小刚,屈春燕.基于子带干涉测量技术的巴基斯坦地震形变获取研究[J].地球物理学报,2016,59(4):1371-1382. |
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| 作者姓名： | 庾露 单新建 宋小刚 屈春燕 |
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| 作者单位： | 1. 中国地震局地质研究所, 地震动力学国家重点实验室, 北京 100029;2. 广西壮族自治区遥感中心, 南宁530023 |
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| 基金项目： | 国家自然科学基金(41461164002);中国地震局地质研究所所长基金(IGCEA1404);地震动力学国家重点实验室自主研究课题(LED2013A02);中央高校基本科研业务费专项资金(14CX02110A)联合资助 |
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| 摘 要： | 2013年9月24日发生在巴基斯坦俾路支省(Balochistan)境内阿瓦兰县(Awaran)的MW7.7级地震,在地表产生了最大达10m的滑动量.利用TerraSAR-X短波雷达数据获取的InSAR同震形变场产生了密集且大范围的干涉条纹,给后续的相位解缠带来困难.而子带干涉法是一种无需或只需进行少量相位解缠,即可获得绝对相位差的新方法.其主要思路是通过缩减带宽以增长波长,从而减少干涉条纹数,降低解缠难度或不需解缠直接得到绝对相位差.但由于带宽的缩减,导致噪声的增大和旁瓣带来的额外干扰,使干涉图质量下降,因此在子带干涉参数选取、噪声滤波以及处理流程等方面需要特殊处理,特别是子带的中心频率和带宽的选取会很大程度地影响测量精度.首先选取典型DEM实验区,以干涉图相干性和误差为评价指标,利用逐步参数选取法,研究相关参数对子带干涉测量的影响,制定最优的参数方案,认识参数选取的原则和方法.在此基础上,将子带干涉应用于巴基斯坦地震的同震形变场获取.最后,将子带干涉、Landsat 8光学影像的交叉频谱相关法、offset-tracking、常规DInSAR获取的同震形变场进行比较,并与模型拟合的形变场进行对比分析.结果表明,子带干涉虽然会受失相干的影响,其提取的形变场范围相较于Landsat 8和offset-tracking有所缺失,但在共同覆盖的区域其精度和噪声水平更优,相比较于常规DInSAR,更适用于条纹密集和形变量大的地区.
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| 关 键 词： | 子带干涉 巴基斯坦地震 同震形变 |
| 收稿时间： | 2015-11-11 |
Deformation of the 2013 Pakistan MW7.7 earthquake derived from sub-band InSAR |
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| YU Lu;SHAN Xin-Jian;SONG Xiao-Gang;QU Chun-Yan.Deformation of the 2013 Pakistan MW7.7 earthquake derived from sub-band InSAR[J].Chinese Journal of Geophysics,2016,59(4):1371-1382. |
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| Authors: | YU Lu;SHAN Xin-Jian;SONG Xiao-Gang;QU Chun-Yan |
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| Institution: | 1. State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China;2. Guangxi Remote Sensing Center, Nanning 530023, China |
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| Abstract: | On September 24, 2013, an MW7.7 earthquake strok Awaran, Balochistan Province, Pakistan, causing large strike slip up to 10 m. The coseismic deformation field, produced by TerraSAR-X short wave radar data, shows dense and extensive interference fringes which bring difficulties to thephase unwrapping. The sub-band InSAR is a new method for obtaining absolute phase, with a little or without phase unwrapping. This method shortens the bandwidth to increase the wavelength, and could reduce the number of fringes, which decreases the difficulty of phase unwrapping. However the noise and the extra interference of sidelobes will increase and the interferogram quality will decline, while the bandwidth reduces. More consideration should be taken into the parameter selection, noise filtering and processing flow, especially the selection of center frequency and bandwidth. In this paper, we first select the typical DEM experiment zone as the research area, and study the effect of parameter selection on sub-band InSAR with coherences and elevation errors as the evaluation index. Then, we apply the optimal parameter scheme to derive the coseismic deformation field of Pakistan. The coseismic deformation, extracted by sub-band interference, Landsat 8 optical images cross-spectrum correlation, offset-tracking, and conventional DInSAR separately, are analyzed and compared with the deformation field from modeling. It indicates that sub-band InSAR performs batter in precision and noise level, in spite of the slight influence of decorrelation and loss of the extracted deformation field, compared with Landsat-8 and offset tracking. Therefore this method is more suitable to be applied in areas with large deformation and dense fringes. |
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| Keywords: | Sub-band InSAR Pakistan earthquake Coseismic deformation |
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