Land subsidence is a major factor that affects metro line (ML) stability. In this study, an improved multi- temporal interferometric synthetic aperture radar (InSAR) (MTI) method to detect land subsidence near M...Land subsidence is a major factor that affects metro line (ML) stability. In this study, an improved multi- temporal interferometric synthetic aperture radar (InSAR) (MTI) method to detect land subsidence near MLs is presented. In particular, our multi-temporal InSAR method provides surface subsidence measurements with high observation density. The MTI method tracks both point-like targets and distributed targets with temporal radar back- scattering steadiness. First, subsidence rates at the point targets with low-amplitude dispersion index (ADI) values are extracted by applying a least-squared estimator on an optimized freely connected network. Second, to reduce error propagation, the pixels with high-ADI values are classified into several groups according to ADI intervals and processed using a Pearson correlation coefficient and hierarchical analysis strategy to obtain the distributed targets. Then, nonlinear subsidence components at all point-like and distributed targets are estimated using phase unwrapping and spatiotemporal filtering on the phase residuals. The proposed MTI method was applied to detect land subsidence near MLs of No. 1 and 3 in the Baoshan district of Shanghai using 18 TerraSAR-X images acquired between April 21, 2008 and October 30, 2010. The results show that the mean subsidence rates of the stations distributed along the two MLs are -12.9 and -14.0 ram/year. Furthermore, three subsidence funnels near the MLs are discovered through the hierarchical analysis. The testing results demonstrate the satisfactory capacity of the proposed MTI method in providing detailed subsidence information near MLs.展开更多
Shanghai is planning to launch a strategic research of new round of development in 2050,carry out future urban planning research in 2040,and started start the implementation of thirteenth five-year development plannin...Shanghai is planning to launch a strategic research of new round of development in 2050,carry out future urban planning research in 2040,and started start the implementation of thirteenth five-year development planning research. This paper firstly analyzed the relationship between Big Cloud Movement and Maker,and introduced current development situation of makers in Baoshan District of Shanghai. Then,according to current development situation,it came up with recommendations for the maker culture construction: strengthening the awareness for protection of intellectual property right in the district,building " Internet + X" development model for Baoshan District,establishing maker parks in Baoshan District,actively creating the innovation atmosphere,opening the Big Cloud Movement platform the society and promoting generation of grassroots makers,enhancing the cooperation with adjacent district to realize trans-regional cooperation of innovation talents,and introducing social capitals to help innovation teams to make transformation of innovation results.展开更多
文摘Land subsidence is a major factor that affects metro line (ML) stability. In this study, an improved multi- temporal interferometric synthetic aperture radar (InSAR) (MTI) method to detect land subsidence near MLs is presented. In particular, our multi-temporal InSAR method provides surface subsidence measurements with high observation density. The MTI method tracks both point-like targets and distributed targets with temporal radar back- scattering steadiness. First, subsidence rates at the point targets with low-amplitude dispersion index (ADI) values are extracted by applying a least-squared estimator on an optimized freely connected network. Second, to reduce error propagation, the pixels with high-ADI values are classified into several groups according to ADI intervals and processed using a Pearson correlation coefficient and hierarchical analysis strategy to obtain the distributed targets. Then, nonlinear subsidence components at all point-like and distributed targets are estimated using phase unwrapping and spatiotemporal filtering on the phase residuals. The proposed MTI method was applied to detect land subsidence near MLs of No. 1 and 3 in the Baoshan district of Shanghai using 18 TerraSAR-X images acquired between April 21, 2008 and October 30, 2010. The results show that the mean subsidence rates of the stations distributed along the two MLs are -12.9 and -14.0 ram/year. Furthermore, three subsidence funnels near the MLs are discovered through the hierarchical analysis. The testing results demonstrate the satisfactory capacity of the proposed MTI method in providing detailed subsidence information near MLs.
基金Supported by General Research Project for Education and Science of Shanghai(C16064)Key Project for Undergraduate Education Reform of Colleges and Universities in Shanghai"Research and Practice of Interdisciplinary Cooperation in Shipping Talent Cultivation from the Perspective of Innovation and Entrepreneurship Education"
文摘Shanghai is planning to launch a strategic research of new round of development in 2050,carry out future urban planning research in 2040,and started start the implementation of thirteenth five-year development planning research. This paper firstly analyzed the relationship between Big Cloud Movement and Maker,and introduced current development situation of makers in Baoshan District of Shanghai. Then,according to current development situation,it came up with recommendations for the maker culture construction: strengthening the awareness for protection of intellectual property right in the district,building " Internet + X" development model for Baoshan District,establishing maker parks in Baoshan District,actively creating the innovation atmosphere,opening the Big Cloud Movement platform the society and promoting generation of grassroots makers,enhancing the cooperation with adjacent district to realize trans-regional cooperation of innovation talents,and introducing social capitals to help innovation teams to make transformation of innovation results.