融合CORS网与时序InSAR研究北京地区地面形变

Study on Land Subsidence by Combining CORS Networkand Time Series InSAR in Beijing Area

为提高地面形变监测的时空分辨率以及监测精度,采用CORS网与时序InSAR监测相融合的方法,对北京地区2018~2020年地面垂直方向形变进行研究。首先在InSAR监测量中去除极浅地表影响;然后对CORS站数据进行低频重构;最后以CORS网为基准,对InSAR监测时序进行整体平差,获得融合形变结果。结果表明,融合CORS网和InSAR监测能有效利用CORS网连续观测的优势,获取连续一致的高时空分辨率形变结果,融合方法在构建高分辨率与高精度地面形变时间序列中具有一定优势。在地面垂直方向上,朝阳区、通州区、大兴区中南部地面沉降最为明显,最大年平均形变速率达到-90 mm/a;昌平区中西部、海淀区西部、门头沟区东部等地存在较为明显的抬升,年平均形变速率约为10~20 mm/a;其他地区地面年平均形变速率约为-10~10 mm/a,相对变化较小,较为稳定。

To improve the spatio-temporal resolution and accuracy of land deformation monitoring,we adopt the fusion method of CORS network and time series InSAR to study the vertical deformation in Beijing from 2018 to 2020.First,we remove the very shallow surface impact from the InSAR monitoring data.Then,the data of CORS stations are reconstructed in low frequency.Finally,based on CORS network,the InSAR monitoring time series is integral adjusted to obtain the fusion deformation.The results show that the fusion method of CORS network and InSAR monitoring can effectively use the continuous observation advantage of CORS network to obtain continuous and consistent deformation with high spatio-temporal resolution.The fusion method has certain advantages in building high-resolution and high-precision land deformation time series.In the vertical direction,the land subsidence in Chaoyang district,Tongzhou district and mid-southern Daxing district is the most obvious,and the maximum average annual deformation rate reaches-90 mm/a.The mid-western Changping district,western Haidian district and eastern Mentougou district have relatively obvious uplift,and the average annual deformation rate is about 10-20 mm/a.The average annual deformation rate in other regions is about-10-10 mm/a,with relatively small changes and relative stability.