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蒋锐龚清勇朱岱寅朱兆达 《数据采集与处理》2017,32(2):375-381
多基线干涉合成孔径雷达(Interferometic synthetic aperture radar,InSAR)利用长短基线之间的关系,能够获得优于单基线InSAR的高程测量结果。本文针对多基线InSAR的数据特点,提出了基于信号子空间估计的多基线InSAR干涉相位图滤波方法。该方法将不同长度基线下所获得干涉相位图中同一像素单元信号作为一个训练样本,通过信号子空间的估计完成多基线InSAR干涉相位图滤波。仿真实验结果表明,本文方法可以在运算时间相当的情况下,获得优于回转均值滤波算法和回转中值滤波算法的滤波性能,是一种可满足实时处理要求的有效的多基线InSAR干涉相位图滤波方法。 相似文献
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阐述了分布式InSAR目标三维定位原理,分析了干涉基线与空间状态测量之间的关系;给出了干涉基线的完整定义,将干涉基线分解为空间域干涉基线和时间域干涉基线,其中时间域干涉基线通过主星的绝对定轨结果获得,空间域干涉基线主要通过高精度星间相对定位结果获得;分析了卫星轨道速度、平台姿态测量、天线安装等误差对干涉基线测量精度的影响,讨论了不同基线测量体制对姿态精度的要求差异,为分布式InSAR的空间状态测量方案设计及相关测量手段精度指标的论证提供了技术支撑。 相似文献
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极化干涉理论的发展以及全极化卫星的发射,为极化干涉的研究应用提供了广阔的发展空间,开展极化干涉SAR提取DEM的研究对于解决单极化干涉SAR在植被覆盖区DEM提取精度较低的问题具有重要意义。基于山东泰安地区的一对ALOS PALSAR全极化干涉数据,利用相干性最优方法和最大化相位中心分离的方法获取极化干涉信息,并通过对优化后干涉信息的滤波、解缠、基线精确估计等处理来提取DEM,最后将相干优化的结果与传统HH、HV、VV单极化干涉结果进行对比分析。结果表明:优化方法较单极化干涉方法可以有效降低干涉图的噪声,减少相位解缠的残差点,提高解缠相位的质量,并且不同优化方法之间还存在一定差异,数值半径方法获取的DEM精度要好于其他两种优化方法;通过等值线-Goldstein二级干涉SAR滤波方法可进一步提高单极化和优化干涉图的质量,降低残差点,提高相位质量,在水体覆盖的区域通过滤波窗口的设置可以很好地改善DEM的精度。 相似文献
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基于分块技术的相位展开算法 总被引:1,自引:1,他引:1
对干涉相位图的相位展开是干涉合成孔径雷达处理过程中的重要步骤,也是干涉合成
孔径雷达理论与应用研究的难点所在.在充分利用干涉相位图中的干涉条纹信息的基础上,提出
了一种基于分块技术的相位展开算法.首先对干涉相位图做了分块处理,块是由干涉条纹线和图
像边界线组成的一个封闭的区域,在一个块内不存在相位跳跃,即在块内的相位展开已经完成.
在下一步对全图做相位展开时,再逐块进行.最后通过后处理技术进行错误校正.通过对真实数
据的实验和与传统方法的比较,证实了算法的有效性和稳定性. 相似文献
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提出了两副雷达天线在平面内绕环时的干涉逆合成孔径雷达(Inverse synthetic aperture radar, ISAR)成像算法.现有的干涉ISAR成像研究通常忽略了天线几何位置对成像影响,将天线设置为仅在高度上有差别的两副垂直天线.针对这一情况,本文推导了当两副雷达天线不垂直时、特别是在平面内圆周绕环时的干涉ISAR测高算法.研究结果表明,干涉ISAR高程测量不仅与基线长度有关,还与散射点横距坐标有关,于是需要对散射点横距进行估计.仿真结果验证了在此情况下干涉ISAR测高公式的正确性,并进一步分析了天线基线与有效基线之间夹角的变化对测高精度的影响.经统计,目标高度平均测量误差低于3%,几乎达到原两副天线垂直时的测高精度. 相似文献
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利用干涉SAR的DEM做大区域测图应用中,针对干涉SAR多条带拼接时出现的重叠区高程不一致问题,首次提出了利用条带间重叠区连接点进行多条带联合定标方案,减少了地面控制点的数量需求,降低了野外采集地面控制点的工作量,解决了多条带干涉SAR数据的高程不一致问题,突破了干涉SAR技术用于大区域测图的瓶颈。同时为了解决大区域多普勒中心频率的漂移问题,提出利用控制点估计多普勒中心频率线性漂移的方法。利用中国科学院电子学研究所自主设计、研制的机载干涉SAR系统数据,进行了定标处理实验,验证了方法的正确性和有效性。 相似文献
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基于外部DEM的InSAR图像配准方法研究 总被引:2,自引:0,他引:2
雷达图像的配准是进行雷达干涉测量(SAR Interferometry, InSAR)处理的关键,为了保证干涉相位图或形变相位图反映真实地面特性,需要雷达图像之间亚像元级精度的配准。首先综述了已有的基于外部DEM的InSAR图像配准方法的思路及其不足之处,并提出了一种全新的思路:以图像之间的相干性作为目标函数,利用搜索的方法实现了雷达成像方位向和距离向的最优时间常数的估计,从而实现雷达图像之间亚像元级配准;还进一步推导了数字高程模型(Digital Elevation Model, DEM)的误差对算法精度影响的一个更加严密的表示。结论表明,在利用精确轨道数据的情况下,美国航天飞机测地计划SRTM获得的地形数据的精度可以满足精确雷达图像配准的要求。结果表明,利用基于外部DEM算法配准雷达图像在山区和大的时间基线情况下要优于常规相干多项式配准方法,理论上可以达到百分之一个像素的配准精度。 相似文献
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针对丰富植被地区散射中心高度差去相关的问题,提出了一种结合最优相干运算的Pol-In-SAR相干配准方法,讨论了Pol-InSAR复图像配准过程中需要考虑的几个关键问题,并以天山地区SIR-C/SLC复图像的配准结果证明了方法的有效性。 相似文献
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Chaoying Zhao Qin Zhang Xiaoli Ding Jing Zhang 《International journal of remote sensing》2013,34(11):3443-3455
This article presents a new modified Goldstein synthetic aperture radar (SAR) interferogram filter algorithm, named the iterative Goldstein filter. The main idea of this approach is to iteratively filter the SAR interferogram, by determining the filtering parameter alpha adaptively with respect to the pseudo-correlation value of the original and/or last filtered interferograms several times. The filter can be stopped automatically by pre-setting the threshold of mean value and the improvement of pseudo-correlation in given filter windows. Experimental results with both a simulated digital elevation model (DEM) interferogram and real SAR deformation interferogram show an improvement in the new algorithm results compared with those using the Goldstein filter, and its enhanced version, the Baran filter. In addition, from a pseudo-correlation map of the iteratively filtered interferogram, some valuable information can also be abstracted based on the signal residues. 相似文献
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《Displays》2023
Synthetic aperture radar (SAR) interferometry is a high-resolution microwave remote sensing imaging method. Over the past two decades, many researchers working on remote sensing have applied this technology in various disciplines, including environmental monitoring, disaster monitoring, and elevation mapping. However, due to the existence of many influencing factors in the acquisition stage, such as atmospheric humidity and temperature, the reflected wave signals from the ground will be disturbed when received by remote sensing satellites. The presence of noise in interferograms is inevitable. Therefore, the accuracy of interferometric SAR phase denoising and coherence estimation has a decisive impact on the validity of subsequent processing results. In this paper, we pioneer the use of a nested U-net as a feature extractor for interferometric SAR phase and coherence. In addition, we build a phase filter and a coherence estimator by using the residual learning module. With the aim of determining the unique non-local similarity of InSAR images, we use non-local convolution and channel attention mechanisms to extract features in different dimensions of the interferogram. Through quantitative and qualitative experiments, the proposed method performs better in phase denoising and coherence estimation than state-of-the-art methods. 相似文献
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《International journal of remote sensing》2012,33(3):762-780
Due to the lack of accuracy in the navigation system, airborne repeat-pass synthetic aperture radar (SAR) interferometry (InSAR) suffers residual motion errors (RMEs). Previously, we proposed the multisquint technique with point targets (MTPT) to estimate the errors, but its implementation needs improvement and its accuracy has not been assessed by real airborne repeat-pass InSAR data. In this article, the modified MTPT is introduced first. The modification is mainly embodied in two aspects: automatic target selection and noise removing. Because the multisquint (MS) technique is also capable of estimating the RMEs in SAR interferogram and its accuracy has been verified to be high, here it is used as a comparison. In addition, from the viewpoint of MTPT, MS can be understood from another perspective. Using real X-band airborne repeat-pass SAR data, the performance of MTPT is evaluated. The experiment shows that MTPT is able to achieve high accuracy when a large number of point targets are distributed in the observed scene. The limitations of MTPT are also discussed at the end of this article. 相似文献
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Z. W. Li C. Huang D. W. Zheng W. B. Zou Y. K. Shea 《International journal of remote sensing》2013,34(14):2991-3000
We develop a filtering method for SAR interferograms with strong noise based on the concept of the Vondrák filter and the commonly used Goldstein filter. The one‐dimensional Vondrák filter is first extended to two dimensions, and then utilized to smooth the Fourier spectra of overlapped interferogram patches. The smoothed spectra are then back‐transformed into the interferogram space. Experimental results with simulated and real datasets show that the proposed filter can eliminate up to 70% of noise in a SAR interferogram. The results also show a 15% to 35% improvement over some of the existing filters when the noise in an interferogram is strong, and the stronger the noise in an interferogram, the greater is the improvement. 相似文献
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The Digital Elevation Model (DEM) is used in many fields of earth science. It is generated from interferometry SAR (InSAR) using two co-registered radar Single Look complex (SLC) [1], [2] and [3]. This work concerns the exploitation of radar images SLC of the Algiers area acquired on 03 January and 04 January 1994. The former is taken as a master image and the latter as a slave image. We have developed an interferometric process starting with the implementation of a co-registration algorithm for our images, then the elimination of flat-earth phase from the interferogram and at the end we developed a filter in order to minimize the existing noise to have good results after the unwrapping step using our own developed method. 相似文献
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在重复轨道InSAR(synthetic aperture radar interferom etry)处理干涉测量中,干涉图像对在方位向和距离向的频谱偏移是重要的去相干因素,严重影响干涉图的质量,必须对主辅图像对采取适当的频域滤波。本文提出了一种方位向频域滤波和距离向频域滤波的处理流程,即根据频域特征选择在精配准前后做频域滤波。它既能保证精配准的准确度,又能充分降低频谱偏移导致的去相干,从而保证干涉图的高质量。利用4组不同时间间隔和垂直基线距的ERS-1/2 SLC(single look comp lex)数据对进行实验验证,通过对频域滤波前后相干图和残差点的对比分析,验证了本处理流程的有效性。 相似文献