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
Minhang is situated in the southern suburb of Shanghai. It is 30 km from the urban area of Shanghai. In the early 1960s, it was noted for the speed of development in Shanghai’s economy. Now it is a new rising modem i...Minhang is situated in the southern suburb of Shanghai. It is 30 km from the urban area of Shanghai. In the early 1960s, it was noted for the speed of development in Shanghai’s economy. Now it is a new rising modem industrial park—the Shanghai Minhang Economic and Technological Development District. On my visit to the district, Ye Xuyan, Advisor to the General Manager of展开更多
The Shanghai Hongqiao Economic and Technological Development District is an entrance to Shanghai because it is connected to the Hongqiao Airport. The district occupies an area of 65.2 hectares. It is the only way from
Shanghai and Yokohama are very similar in the positions in their respective state economy and in the orbit of eco-nomic structure development. Since industrial districts in Yokohama city were established dozens years ...Shanghai and Yokohama are very similar in the positions in their respective state economy and in the orbit of eco-nomic structure development. Since industrial districts in Yokohama city were established dozens years earlier than Shanghai, the experience of Yokohama must be very useful for Shanghai urban planning.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.
文摘Minhang is situated in the southern suburb of Shanghai. It is 30 km from the urban area of Shanghai. In the early 1960s, it was noted for the speed of development in Shanghai’s economy. Now it is a new rising modem industrial park—the Shanghai Minhang Economic and Technological Development District. On my visit to the district, Ye Xuyan, Advisor to the General Manager of
文摘The Shanghai Hongqiao Economic and Technological Development District is an entrance to Shanghai because it is connected to the Hongqiao Airport. The district occupies an area of 65.2 hectares. It is the only way from
基金the cultural exchange program between Yokohama and Shanghai
文摘Shanghai and Yokohama are very similar in the positions in their respective state economy and in the orbit of eco-nomic structure development. Since industrial districts in Yokohama city were established dozens years earlier than Shanghai, the experience of Yokohama must be very useful for Shanghai urban planning.
