摘要
采用一种改进的基于相位相干性的非线性人工角反射器InSAR解算算法,不仅能有效地避免相位解缠误差,而且对于大尺度形变梯度具有较强的探测能力。将该方法用于四川丹巴县甲居滑坡形变监测试验,获取了位于甲居滑坡上角反射器的形变结果。通过与小基线集InSAR算法以及基于解缠相位的CR-InSAR算法结果比较,该方法更能准确获取非线性形变时间序列结果,合理地揭示了甲居滑坡明显的形变特征。
CR-InSAR is to lay a number of artificial scatterers in the study area to overcome the spatial and temporal decorrelation effect on D-InSAR and to detect high precision deformation of complex ter- rain area. However, when the deformation between two CR points is more than half radar wave- length, phase unwrapping is becoming extremely difficult. At present, common phase unwrapping me^hods used for CR-InSAR are Lambda a!gorithm, minimum cost flow algorithm, et al, but these al- gorithms all require successfully unwrapping. In the paper, we adopt an improved nonlinear artificial corner reflectors InSAR algorithm based on phase coherence. This method can not only avoid the phase unwrapping error effectively, but also has the strong capability to detect the large scale deform- ation gradient. In the separation of nonlinear deformation, according to the different characteristics of atmospheric phase in special and temporal domain, taking atmospheric phase and noise phase together as random error, applying the least square method to calculate nonlinear deformation parameters to re- duce the loss of nonlinear deformation as far as possible. Taking Jiaju landslide located in Danba County of Sichuan Province as an example, we obtain the deformation of the corner reflectors placed in Jiaju landslide. By comparing the result with that of the SBAS InSAR algorithm and the unwrapping phase based CR-InSAR algorithm, it proves that the improved method can obtain the nonlinear time series result accurately and also reveals that Jiaju landslide has obvious deformation characteristics rea- sonably.
出处
《武汉大学学报（信息科学版）》
EI
CSCD
北大核心
2017年第3期377-383,共7页
Geomatics and Information Science of Wuhan University
基金
国家973计划(2014CB744703)
国家自然科学基金(41372375
41274005
41304016
41202245)~~
关键词
甲居滑坡
非线性形变
监测
人工角反射器
Jiaju landslide
nonlinear deformation
monitoring
artificial corner reflectors
