GACOS辅助时序InSAR的北京市地面沉降监测与分析OA

Regarding the issue of the impact of atmospheric delay effects on the accuracy of surface deformation monitoring using synthetic aperture radar interferometry(InSAR),this article takes typical subsidence areas in Beijing as the research object,selects 20 ascending Sentinel-1A C-band SAR images throughout 2021,uses the GACOS model to correct tropospheric delay errors,and,combined with the SBAS-InSAR technique,inverts the annual average deformation rate field of the main urban area.The results show that GACOS correction effectively removes atmospheric delay errors and significantly improves deformation monitoring accuracy,as evidenced by a reduction in the mean standard deviation of interferogram phases after correction.In 2021,three distinct subsidence zones were identified in the main urban area of Beijing:Beijing Capital International Airport,the adjacent belt of the Beijing-Shanghai Expressway,and the ecological corridor along the Beijing-Harbin Railway and the Chaobai River.The peak annual average subsidence rates reached-162.19,-96.37,and-54.43 mm/year,respectively(negative values indicate subsidence).The subsidence areas exhibit a funnel-shaped distribution,and the underlying causes may be associated with dense road networks,urban construction,and excessive groundwater extraction.