【作者】 张会战；

【导师】 独知行；

【作者基本信息】 山东科技大学 ， 大地测量学与测量工程， 2008， 博士

【摘要】 相位解缠是InSAR数据处理的关键技术,解缠相位精度直接影响着DEM和变形监测的精度,因此一直是InSAR技术研究的热点。本文分析和总结了目前相位解缠研究的成果和存在的问题,重点研究了枝切线相位解缠算法、质量图指引算法和掩模切割算法的优势,针对Goldstein枝切线的大量冗余、枝切线的安置不考虑干涉像素质量的问题,从枝切线的连接策略和引入质量图来指导枝切线的安置两个方面做了研究和改进。1.采用最小生成树的Prim算法有效地减少了枝切线的冗余,消除了枝切线中的圈和贯通枝切线,改善了Goldstein算法解缠结果。2.提出了基于度的最短路径算法,枝切线的改进效果稍优于Prim算法,而且运算速度快。3.在Goldstein相位解缠算法中引入干涉图的质量信息,一是先用质量掩膜屏蔽低质量像素,再实施Goldstein算法;一是采用阈值把质量图分成不同质量区域,优化加权的Goldstein枝切线。实验证明,改进后的枝切线长度和不连续长度显著减少,解缠结果的精度明显提高。更多还原

【Abstract】 Phase unwrapping is a key technique in data processing of Synthetic aperture radar interferometry (InSAR) and its accuracy directly impacts on the precision of digital elevation models (DEM ) and deformation monitoring, so it is still a hotspot in the research of InSAR. In the paper achievements and problems of current phase unwrapping algorithms are analyzed and summarized, whereas main study is laid on the advantages of branch-cut phase unwrapping algorithm, quality-guided path following algorithm and mask cut algorithm. Therefore, Goldstein’s phase unwrapping algorithm is studied in two fields of the linking strategy of branch-cuts and introduction of quality maps in guiding the branch-cuts’ placement to solve the problems that there are a large number of redundancies in branch-cuts and quality maps are not considered in placement of the branch-cuts.1. Goldstein’s branch-cuts are optimized by using minimum spanning tree, as a result, the redundancies in the branch-cuts are effectively reduced, cycles and cross branch-cuts are eliminated. It is demonstrated that solutions are improved evidently.2. The shortest path based on degrees is put forward. The new algorithm makes the length of the branch-cuts shorter than Prim algorithm and operation faster.3. Quality information of interference pattern is applied to Goldstein’s phase unwrapping algorithm. Firstly, Goldstein’s algorithm is executed after bad quality pixels are masked by mask-cut. Secondly, a quality-map is separated into regions of different quality value according to thresholds and then weighted branch-cuts are optimized.Experiments prove that the length of branch-cuts and magnitude of discontinuities are remarkably reduced and unwrapped results are evidently improved with branch-cuts optimized.更多还原