延安新区地面沉降分布及影响因素的时序InSAR监测分析

在时间序列合成孔径雷达干涉测量（interferometric synthetic aperture radar, InSAR）形变监测研究中，常规三角反射器越来越多地被用作点目标，但在升降轨观测场景下无法同时满足获取多角度形变信息的要求，需要针对特定数据类型量身定制满足监测需求的角反射器。构建了一套角反射器设计和精度验证方案，根据X波段雷达卫星拍摄特点设计了同时满足升降轨监测场景双向可调节矩形角反射器，并将其布设在监测区公路边坡上，通过人工模拟二维形变场验证时间序列InSAR对双向矩形角反射器的探测精度。实验结果表明，在有效消除像素点旁瓣效应的情况下，所设计的双向矩形角反射器后向散射信息最强像素点被识别；精确计算出在2018-05-13—2018-05-24期间，有2个角反射器发生了移动，形变探测的中误差为0.6 mm。时间序列InSAR对设计的双向矩形角反射器形变具有很高的敏感度。

Analysis of Land Subsidence Distribution and Influencing Factors in Yan'an New District Based on Time Series InSAR

  Objectives  In the research of time-series interferometric synthetic aperture radar (TS-InSAR) deformation monitoring, the conventional triangular reflectors are increasingly used as point targets. But the conventional triangular reflectors cannot meet the requirements of obtaining multi-angle deformation information on ascending and descending track scenes. They need to be tailored for specific datasets to meet monitoring needs.  Methods  A set schemes for corner reflector design and accuracy verification are constructed.According to the characteristics of X-band radar satellite satellite, a two-way adjustable rectangular corner reflector is designed to meet the monitoring scene of the ascending and descending track. Due to the relationship between the radar cross section(RCS) and the size of the corner reflector, the side length of the bidirectional rectangular corner reflector is calculated to be 0.35 m.Ten bidirectional rectangular corner reflectors are placed on the side slope of the highway in the monitoring area.By artificially simulating the two-dimensional deformation, the detection accuracy and reliability of the TS-InSAR on the bidirectional rectangular corner reflector is verified.  Results  Under the condition of effectively eliminating the sidelobe effect of the pixel, the designed bidirectional rectangular corner reflector maintains a high and stable backscattering intensity, which can be easily extracted. Through the analysis of the weather conditions at the time of imaging, heavy rainfall has a certain influence on the backscattering intensity of corner reflectors. Under the blind experimental conditions of artificially adjusting the height of the corner reflector, CR1 and CR2 are moved between May 13, 2018 and May 24, 2018. The root mean square error is 0.6 mm. The deformation detection accuracy reaches the sub-millimeter level.  Conclusions  The TS-InSAR is highly sensitive to the deformation of the designed bidirectional rectangular corner reflector. The bidirectional rectangular corner