面向复杂大气扰动的GB-InSAR相位误差补偿方法

Phase Error Compensation Method for Complex Atmospheric Disturbance in GB-InSAR

  • 摘要: 大气扰动是地基干涉合成孔径雷达(GB-InSAR,Ground-Based Interferometric Synthetic Aperture Radar)测量的主要误差源之一。在复杂大气条件下,常规的大气相位补偿方法不再适用,本文提出了一种基于PS(Permanent Scatterer,永久散射体)技术的改进方法。该方法首先通过Delaunay三角网建立临近PS对,分析各临近PS对的差分相位序列标准差,实现PS集合中的噪声点或部分形变点的滤除;然后根据气象数据估计出参考大气相位序列,通过计算剩余PS的干涉相位序列与参考大气相位序列的MIC(Maximal Information Coefficient,最大互信息系数),结合空间维相干系数,采用双阈值实现稳定 PS的选择;最后采用Kriging插值拟合方法,实现复杂大气条件下的大气相位估计。采用本文所提方法,对九道拐区域实测数据进行了处理,相比于常规方法,有效降低了大气相位补偿误差,保证了GB-InSAR的形变测量精度。

     

    Abstract: ‍ ‍Atmospheric disturbance is one of the main error sources in ground-based interferometric synthetic aperture radar (GB-InSAR) measurements. Under complex atmospheric conditions, conventional atmospheric phase compensation methods are no longer applicable. This paper proposes an improved method based on PS (Permanent Scatterer) technology. Firstly, the method establishes adjacent PS pairs through the Delaunay triangulation network, and analyzes the standard deviation of the differential phase sequence of each adjacent PS pair. Those noisy points or partial deformation points in the PS set can be filtered out. Then, the reference atmospheric phase sequence is estimated based on the meteorological data. By calculating the MIC (Maximal Information Coefficient) of the interference phase sequence of the remaining PS and the reference atmospheric phase sequence, together with the spatial coherence, dual thresholds are used to achieve the stable PS selection. Finally, the Kriging interpolation fitting method is used to achieve atmospheric phase estimation under complex atmospheric conditions. The method proposed in this paper is used to process the measured data in the Jiudaoguai area. Compared with the conventional methods, the atmospheric phase compensation error is effectively reduced, and the deformation measurement accuracy of GB-InSAR can be better guaranteed.

     

/

返回文章
返回