李鹏, 高梦瑶, 李振洪, 王厚杰. 阿尔金断裂带宽幅InSAR对流层延迟估计方法评估[J]. 武汉大学学报 ( 信息科学版), 2020, 45(6): 879-887. DOI: 10.13203/j.whugis20190236
引用本文: 李鹏, 高梦瑶, 李振洪, 王厚杰. 阿尔金断裂带宽幅InSAR对流层延迟估计方法评估[J]. 武汉大学学报 ( 信息科学版), 2020, 45(6): 879-887. DOI: 10.13203/j.whugis20190236
LI Peng, GAO Mengyao, LI Zhenhong, WANG Houjie. Evaluation of Wide-Swath InSAR Tropospheric Delay Estimation Methods over the Altyn Tagh Fault[J]. Geomatics and Information Science of Wuhan University, 2020, 45(6): 879-887. DOI: 10.13203/j.whugis20190236
Citation: LI Peng, GAO Mengyao, LI Zhenhong, WANG Houjie. Evaluation of Wide-Swath InSAR Tropospheric Delay Estimation Methods over the Altyn Tagh Fault[J]. Geomatics and Information Science of Wuhan University, 2020, 45(6): 879-887. DOI: 10.13203/j.whugis20190236

阿尔金断裂带宽幅InSAR对流层延迟估计方法评估

Evaluation of Wide-Swath InSAR Tropospheric Delay Estimation Methods over the Altyn Tagh Fault

  • 摘要: 近年来,宽幅合成孔径雷达干涉测量(interferometric synthetic aperture radar,InSAR)技术已被广泛用于地质灾害普查、地壳形变监测等方面,但对流层相位延迟影响极大限制了大范围、缓慢构造形变监测的精度。以覆盖地形起伏强烈的阿尔金断裂带西段的两类宽幅InSAR时间序列为例,分析了欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)、InSAR通用型大气改正在线服务(generic atmospheric correction online service for InSAR,GACOS)、地形相关线性模型这3类方法对大尺度对流层延迟的改正效果。结果表明,经GACOS改正后的Envisat ASAR与Sentinel-1宽幅InSAR干涉图序列的相位标准差均值削减量分别可达68.1%和54.5%,整体优于ECMWF和地形相关线性改正方法,能够为国内外InSAR用户开展宽幅InSAR大范围地质灾害监测等应用提供关键可靠的支持。

     

    Abstract: In recent years, wide-swath (WS) interferometric synthetic aperture radar (InSAR) technique that has the potential to produce continental-scale maps has been widely used in geological disaster survey and crustal deformation monitoring. However, the impact of tropospheric delay greatly limits its accuracy in mapping small amounts of ground deformation over large spatial areas. Three common used methods, that is ECMWF (European Centre for Medium-Range Weather Forecasts), GACOS (generic atmospheric correction online service for InSAR) and topography-correlated linear relationship, are evaluated to investigate their statistical performance with WS InSAR time series derived from Envisat ASAR ScanSAR and Sentinel-1 TOPOSAR modes over the western segment of the Altyn Tagh Fault. The results show that the GACOS correction method is superior to the other two methods and performs best in capturing both topography-correlated and turbulent mixing tropospheric delays. For Envisat ASAR and Sentinel-1 datasets, the mean reduction of phase standard deviation after GACOS correction can reach 68.1% and 54.5% respectively. The linear correction method can perform relatively well in large-scale areas with rough topography when vertical atmospheric stratification dominates the tropospheric delay. Due to a lack of ground meteorological observation, ECMWF products with limited spatial and temporal resolution cannot accurately reveal the local details. As a fast, robust and effective online service for tropospheric delay estimation and correction, GACOS products can provide critical and reliable support for global InSAR users in large-scale geological disaster applications.

     

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