Seasonal Deformation of Permafrost in Wudaoliang Basin in Qinghai-Tibet Plateau Revealed by StaMPS-InSAR

Abstract

Permafrost is extremely sensitive to variance in external hydrothermal conditions. InSAR has advantages in monitoring surface deformation with decent temporal and spatial resolution as well as millimeter precision. In particular, the StaMPS-InSAR method can remove the disturbances of inaccurate digital elevation model (DEM), atmospheric delays and spatiotemporal decorrelation for an accurate estimation of temporal surface deformation. In this paper, a set of ascending and descending Sentinel-1 imageries spanning from March 2017 to June 2018 were acquired and processed by StaMPS-InSAR in order to investigate dynamic changes of permafrost in Wudaoliang Basin, Qinghai-Tibet Plateau (QTP). The results revealed that significant seasonal changes of permafrost, namely subsidence (thawing) in summer and uplift (freezing) in winter, can be observed throughout the Wudaoliang region. This study shows the StaMPS-InSAR analysis on Sentinel-1 datasets has great potential in regional permafrost investigation.     

基于时序合并的PS-InSAR方法在雄县及周边区域地表形变监测中的应用

本文提出了一种基于时序合并的PS-InSAR(TSC-PS-InSAR)监测方法,提取雄县及周边区域地表形变信息。形变区域最大沉降速率为-79 mm/a,沉降原因为地下水超采。结果表明,TSC-PS-InSAR方法在无需先验模型的条件下,能显著提高PS目标数量,且监测结果与StaMPS方法提取的形变信息在沉降趋势及沉降量级上保持了良好的一致性,验证了本文方法在实际应用中的可靠性和可行性。     

一种联合GACOS与线性大气校正的StaMPS PSI时序分析方法

雷达信号通过大气层时,会产生路径延迟,从而影响InSAR测量精度。常规靠时空滤波的时序InSAR分析方法,虽能削弱其影响,但仍存在一定局限。其中StaMPS PSI方法凭借适用范围广、开源等优点,受到众多学者的青睐。为此本文以香港地区为例,提出了一种联合GACOS与线性大气校正的StaMPS PSI时序分析方法,并与常规StaMPS PSI对比,最后使用GNSS观测数据对InSAR结果进行验证。结果表明：在SAR数据集较为丰富的情况下,常规时序分析方法能较好地克服大气延迟影响,但相比而言,本文提出的新方法更能反映出真实的地表形变。