【作者】 任坤；

【导师】 是湘全；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2005， 博士

【摘要】 数字高程模型(DEM)是重要的基础地理信息数据,在军事和民用领域有着重要的应用价值。合成孔径雷达干涉测量技术(InSAR)作为一种极具发展潜力的对地观测技术,被认为是获取大范围高质量DEM数据的最有效手段之一。在中欧国际合作第五框架中“ANFAS”项目的资助下,本文开展了基于星载合成孔径雷达干涉测量技术的DEM生成的研究。 本文以获取高质量的DEM为最终目的,研究了星载重复轨迹干涉测量生成数字高程模型的基本理论和实际数据处理技术,并利用ERS-1/2串行数据实现了荆江分洪区的高程测量。本文主要工作如下: 1.基于干涉相位的统计特性,讨论了干涉相位与相干系数和视数的关系,重点分析了干涉相位和相干系数的估计问题,给出了实现无偏估计的复相干与多视处理相结合的处理方法。 2.在讨论影响干涉相位质量因素的基础上,深入分析了基线去相干和多普勒去相干的成因及其对干涉相位的影响。针对ERS-1/2数据,设计并实现了距离和方位向上的谱移滤波;并以相干系数为干涉相位质量的评价标准,验证了谱移滤波能够有效消除去相干、改善干涉相位的质量。 3.研究了干涉图形成过程出现的混叠效应对干涉相位质量的影响。分别以相干系数和残差点做为干涉相位图的评价依据,用实际数据分析了消除混叠效应的重采样处理技术的性能,并通过实验表明过采样处理技术能够有效地改善干涉相位质量。 4.深入地探讨了平地相位的物理内涵,提出绝对平地相位和相对平地相位的概念;从理论上证明了频移法去除相对平地相位的原理,并提出一种基于地理定位的去绝对平地相位的方法。 5.讨论基线对InSAR系统性能的影响,在分析比较几种典型基线估计方法性能的基础上,依据基线的定义提出一种简单有效的基线估计方法——配准轨道法。 6.在讨论前向地理编码和后向地理编码方法的基础上,基于后向地理编码实现了基于DEM的干涉相位图模拟;并与地形模拟结合起来构成干涉相位模拟器,实现了基于模拟地形数据和真实轨道数据的相位图模拟。 7.在上述研究的基础上,给出InSAR处理的详细处理流程,并依据此流程使更多还原

【Abstract】 Digital elevation model (DEM) is the fundamental infrastructure of geographical information systems and has wide applications in both military and civil areas. As a powerful earth-observation technique, synthetic aperture radar interferometry (InSAR) is thought as one of the effective techniques for obtaining large-area and high-quality DEMs. Under the support of Sino-Euro cooperative project—ANFAS, this dissertation studies thegeneration of DEMs using space-borne InSAR.With the aim of obtaining high-quality DEM, this dissertation studies the fundamental theory and processing techniques of space-borne repeat-tracking interferometry, and generates DEM of Jing-Jiang retention using ERS-1/2 tandem data. Main works are included as follows:1. Based on the statistical properties of interferometric phases (IP), the effects of coherence and looks on IP are discussed and an unbiased estimation method of the IP and coherence is proposed with the combination of complex coherence and multi-look processing.2. Under the discussion of IP decorrelation, a thorough analysis is conducted of generating mechanisms of baseline decorrelation and Doppler decorrelation and their effects on IP. By using ERS-1/2 data, spectrum-shift filtering scheme in both range and azimuth directions is implemented. With the coherences as the judgment of IP qualities, it is shown that the spectrum-shift filtering can remove the decorrelation and thus improve the IP quality.3. The alias effects caused by complex-conjugate multiplications on IP quality are analyzed. With the coherence and residuals as the judgment, the performances of re-sampling techniques for removing alias effects are discussed by using ERS-1/2 data and it is pointed out that the over-sampling techniques can greatly improve IP quality.4. The physical meanings of flat-earth phases are thoroughly discussed and the concepts of flat-earth phases and relative flat-earth phases are established. It is proved that the spectrum-shift method can only remove relative flat-earth phases. A geolocation-based method is proposed to remove flat-earth effects.5. The effect of baseline on InSAR system is discussed. With comparisons of several更多还原