InSAR大气相位建模与估计及差分水汽分解

发布时间：2018-01-25 07:36

  本文关键词： InSAR 大气相位 建模与估计 短基线集 水汽反演　出处：《中南大学》2014年硕士论文　论文类型：学位论文

【摘要】：摘要：大气水汽的时空变化是影响星载合成孔径雷达(SAR)大地测量精度的关键因素。1994年,Massonnet等首次识别出了InSAR中的大气效应,至今已有不少学者在InSAR大气改正方面展开了大量研究。同时,通过利用InSAR中的大气延迟来反演水汽含量的变化,也促使了InSAR在气象学上的应用。基于此,论文主要围绕合成孔径雷达干涉测量(Interfer-ometric Synthetic Aperture Radar, InSAR)过程中大气延迟分量展开研究。主要研究工作如下： (1)对重轨InSAR中大气相位进行定量分析,以更好地理解InSAR大气噪声的特征。对典型区域的ERS Tandem数据进行分析,结果表明,地形起伏越大,相位与地表高程的拟合度越高,对InSAR大气相位的垂直分层部分的建模,指数模型要优于线性模型；同时,在描述InSAR大气相位的紊流部分的结构函数时,Matern模型较传统的球状模型更为理想。该分析结果有助于建立更高精度的重轨InSAR大气相位模型。 (2)为削弱大气延迟对干涉结果的影响以提高InSAR的测量能力,本文在InSAR大气相位特征分析的基础上,研究了一种新的InSAR大气相位建模与估计的方法。该方法首先采用稳健估计确定大气垂直分层部分模型参数,然后基于Matern模型的Kriging插值用于估计大气紊流部分,最后利用估计的大气垂直分层和紊流资料改正InSAR测量结果。结果表明去除大气影响后,InSAR重建DEM更趋近于参考DEM。 (3)借鉴SBAS中短基线组合的构网方式,基于现代测量平差手段,利用时间序列上的多幅InSAR干涉图分解出各SAR成像时刻的水汽分布。其中,假设所有SAR成像时刻的水汽在时间上服从零均值分布,从而增加约束条件解决方程秩亏问题。研究结果表明,反演的水汽值与同步的MERIS较为一致,说明本文提出的InSAR差分水汽分解方法具有较高的可靠性。图22幅,表4个,参考文献55篇
[Abstract]:Abstract: the spatial and temporal variation of atmospheric water vapor is the influence of spaceborne synthetic aperture radar (SAR) geodetic precision key factors.1994, Massonnet first identified the atmospheric effect in InSAR, launched a lot of research has been corrected many scholars in the InSAR atmosphere. At the same time, by changing the delay to inversion of water vapor content by InSAR in the atmosphere, also contributed to the application of InSAR in meteorology. Based on this, the thesis focuses on the interferometric synthetic aperture radar (Interfer-ometric Synthetic Aperture Radar, InSAR) to launch the research component of atmospheric delay in the process. The main research work is as follows:
(1) for the quantitative analysis of atmospheric heavy rail in InSAR phase, in order to better understand the characteristics of InSAR atmospheric noise. The ERS Tandem data in typical areas were analyzed, the results show that the topography is bigger, and the phase of surface elevation fitting degree is high, the atmospheric phase InSAR vertical stratification part modeling, index the model is better than linear model; at the same time, the structure function of turbulent atmospheric phase of the InSAR part description, the spherical model Matern model even more than the traditional InSAR. The ideal model of the heavy rail atmospheric phase analysis results are helpful to establish more accurate.
(2) in order to reduce the impact on the atmospheric delay interference in order to improve the measurement capability of InSAR, based on InSAR analysis of atmospheric phase characteristics, studied a new method of InSAR modeling and estimation of atmospheric phase. This method uses robust estimation to determine the atmospheric vertical layer model parameters, then Kriging interpolation Matern based on the model is used to estimate the atmospheric turbulence, and finally using the estimated atmospheric vertical stratification and turbulence data to correct InSAR measurements. The results show that the removal of atmospheric effects after InSAR reconstruction DEM closer to the reference DEM.
(3) reference network scheme in SBAS short baseline combination, modern surveying adjustment method based on InSAR, using multiple time series interferograms decomposition of water vapor distribution by SAR imaging time. Among them, the assumption that all SAR imaging moment in time to zero mean water vapor distribution, thereby increasing the constraint conditions to solve the equation rank deficient problem. The results show that the inversion of the water vapor values are consistent with the synchronization of MERIS, reliability of the proposed InSAR differential water vapor decomposition method is higher. 22 charts, 4 tables, 55 references

【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P237

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