InSAR技术在监测形变中的干涉条件分析

针对InSAR技术在形变监测领域中的应用,本文从分析D-InSAR的干涉机理对其约束条件出发,重点研究空间去相关和形变梯度这两个关键指标对形变信息提取的影响.研究针对不同系统参数的传感器来展开,并论证这两个因素对干涉测量的限制.本文的创新性工作主要集中在以下几个方面: (1)分析了各传感器参数下的临界坡度范围,进而确立了SAR传感器监测的无信息区域;(2)证明了在植被覆盖区,相干性分解必须考虑体散射分量,并依此对模型进行了修正;(3)明确了形变梯度与相位梯度的差异以及两者的函数关系,并将入射角引入形变梯度函数模型.(4)通过模拟数据和真实数据比较各传感器在不同条件下形变监测的优缺点,在统计分析的基础上进一步验证结论.本文的研究是对干涉测量条件的进一步补充,对于理解干涉成像机理、完善InSAR数值计算模型(形变梯度模型和相干性分解模型)以及帮助研究人员根据研究区域特征选择合适的InSAR数据具有一定的参考价值.

The analysis of conditions for InSAR in the field of deformation monitoring

For InSAR application in deformation monitoring field, we discuss the traditional interferometry basis of D-InSAR and its constraint conditions are summarized in this paper. According to sensors with different system parameters, we focus on spatial decorrelation and deformation gradient as the main clue to quantitatively analyze how these factors impact the deformation extraction and limit the use of interferometry. The study achieves the following: (1) Analyze the range of critical slope for each sensor and the blind areas monitored by SAR are estimated.(2) Volume scattering component must be considered while using coherence decomposition technique in vegetation area and the model is modified. (3) Illuminate the difference between deformation gradient and phase gradient and their function is proposed. Meanwhile, the angle of incidence is introduced to the function of deformation gradient. (4) On this basis, we use a series of representative data to validate the conclusion. This study further extends conditions for InSAR measurements, which also has important reference value and application significance for understanding the interferometry mechanism, establishing improved InSAR numerical model and helping researchers to determine the most appropriate data by different deformation characteristics.