In the past two decades,extensive and in-depth research has been conducted on Time Series InSAR technology with the advancement of high-performance SAR satellites and the accumulation of big SAR data.The introduction ...In the past two decades,extensive and in-depth research has been conducted on Time Series InSAR technology with the advancement of high-performance SAR satellites and the accumulation of big SAR data.The introduction of distributed scatterers in Distributed Scatterers InSAR(DS-InSAR)has significantly expanded the application scenarios of InSAR geodetic measurement by increasing the number of measurement points.This study traces the history of DS-InSAR,presents the definition and characteristics of distributed scatterers,and focuses on exploring the relationships and distinctions among proposed algorithms in two crucial steps:statistically homogeneous pixel selection and phase optimization.Additionally,the latest research progress in this field is tracked and the possible development direction in the future is discussed.Through simulation experiments and two real InSAR case studies,the proposed algorithms are compared and verified,and the advantages of DS-InSAR in deformation measurement practice are demonstrated.This work not only offers insights into current trends and focal points for theoretical research on DS-InSAR but also provides practical cases and guidance for applied research.展开更多
In DEM generation using interferometric synthetic aperture radar(InSAR),the ground control points(GCPs)for refinement and reflattening are usually selected by manual selection,field surveying,GPS points and existing b...In DEM generation using interferometric synthetic aperture radar(InSAR),the ground control points(GCPs)for refinement and reflattening are usually selected by manual selection,field surveying,GPS points and existing basemaps,which may not be completely suitable for consequent processes.We proposed a new method(auto-PS-GCP)of GCP selection based on permanent scatterers,which automatically defines the thresholds for the coherence,amplitude,and amplitude dispersion index to select permanent scatterer as the GCPs.The GCP thinning(auto-PS-GCP-Thin)was further conducted considering the point density,distances among points and terrain conditions.We used a three-stage assessment that includes:(1)phase stability and intensity of the GCPs,(2)RMSEs of the elevations between GCPs and homonymous points in the reference DEM,and(3)generated DEM accuracy.Three areas respectively in the plain,hilly and mountainous regions were selected to verify the proposed methods.The assessment using both SRTM DEM andICESat-2 points shows that the DEM accuracy of auto-PS-GCP-Thin was improved by 20%∼30%for different areas compared to the manual,where the best DEM accuracy of 4.71 m was found in the plain area.It is concluded that the proposed methods are effective and reliable in various areas with different terrain conditions.展开更多
Satellite differential synthetic aperture radar interferometry (DInSAR) has two limitations, i. e. , spatio-temporal decorrelation and atmospheric influence, for the application of regional deformation mapping. This...Satellite differential synthetic aperture radar interferometry (DInSAR) has two limitations, i. e. , spatio-temporal decorrelation and atmospheric influence, for the application of regional deformation mapping. This paper proposed a new approach called time series DInSAR based on permanent scatters (PS) to overcome the limitations, and the relevant mathematical model and computing method are also developed. With the proposed algorithm, the experiments were performed to estimate the subsidence velocity field over Shanghai using 26 ERS-1/2 SAR images acquired from 1992 to 2002. The deformation signatures, atmospheric delay and other errors were separated effectively, and the subsidence velocity field over Shanghai was also derived.展开更多
Considering the joint effects of various factors such as temporal baseline, spatial baseline, thermal noise, the difference of Doppler centroid frequency and the error of data processing on the interference correlatio...Considering the joint effects of various factors such as temporal baseline, spatial baseline, thermal noise, the difference of Doppler centroid frequency and the error of data processing on the interference correlation, an optimum selection method of common master images for ground deformation monitoring based on the permanent scatterer and differential SAR interferometry (PS-DInSAR) technique is proposed, in which the joint correlation coeficient is used as the evaluation function. The principle and realization method of PS-DInSAR technology is introduced, the factors affecting the DInSAR correlation are analysed, and the joint correlation function model and its solution are presented. Finally an experiment for the optimum selection of common master images is performed by using 25 SAR images over Shanghai taken by the ERS-1/2 as test data. The results indicate that the optimum selection method for PS-DInSAR common master images is effective and reliable.展开更多
Shanghai Pudong International Airport(PDIA),with its east side built along the coast with weak geological conditions,is prone to uneven foundation settlement due to the consolidation and compression of soil and erosio...Shanghai Pudong International Airport(PDIA),with its east side built along the coast with weak geological conditions,is prone to uneven foundation settlement due to the consolidation and compression of soil and erosion of coastal tides,affecting the safe operation of the airport.Therefore,it is crucial to conduct dynamic subsidence monitoring within the airport,especially in the runway area.29 scenes of ascending track Sentinel-1A radar images from August 2016 to June 2018 are selected to perform surface deformation inversion based on PS-InSAR and improved SBAS-InSAR for PDIA and its around coastal area.Through cross-validation,the reliability of the time-series InSAR technique for dynamic monitoring of surface deformation of coastal zone infrastructures is confirmed.The results show severely uneven settlement.By combining the monitoring results with the local geological and hydrological dataset,the driving factors of differential deformation of the infrastructures are analyzed,including stratigraphic geological conditions,ground loadings,foundation treatment methods,water erosion,and groundwater level changes.Finally,the time-series deformation characteristics and the causes of PDIA’s runway are emphasized based on the PS deformation results.This case provides a reference for the safety management of critical infrastructure in coastal areas using advanced InSAR technique.展开更多
基金National Natural Science Foundation of China(No.42374013)National Key Research and Development Program of China(Nos.2019YFC1509201,2021YFB3900604-03)。
文摘In the past two decades,extensive and in-depth research has been conducted on Time Series InSAR technology with the advancement of high-performance SAR satellites and the accumulation of big SAR data.The introduction of distributed scatterers in Distributed Scatterers InSAR(DS-InSAR)has significantly expanded the application scenarios of InSAR geodetic measurement by increasing the number of measurement points.This study traces the history of DS-InSAR,presents the definition and characteristics of distributed scatterers,and focuses on exploring the relationships and distinctions among proposed algorithms in two crucial steps:statistically homogeneous pixel selection and phase optimization.Additionally,the latest research progress in this field is tracked and the possible development direction in the future is discussed.Through simulation experiments and two real InSAR case studies,the proposed algorithms are compared and verified,and the advantages of DS-InSAR in deformation measurement practice are demonstrated.This work not only offers insights into current trends and focal points for theoretical research on DS-InSAR but also provides practical cases and guidance for applied research.
基金Supported by the National Key R&D Program of China(2021YFB3900105-2)the National Natural Science Foundation of China(42071371).
文摘In DEM generation using interferometric synthetic aperture radar(InSAR),the ground control points(GCPs)for refinement and reflattening are usually selected by manual selection,field surveying,GPS points and existing basemaps,which may not be completely suitable for consequent processes.We proposed a new method(auto-PS-GCP)of GCP selection based on permanent scatterers,which automatically defines the thresholds for the coherence,amplitude,and amplitude dispersion index to select permanent scatterer as the GCPs.The GCP thinning(auto-PS-GCP-Thin)was further conducted considering the point density,distances among points and terrain conditions.We used a three-stage assessment that includes:(1)phase stability and intensity of the GCPs,(2)RMSEs of the elevations between GCPs and homonymous points in the reference DEM,and(3)generated DEM accuracy.Three areas respectively in the plain,hilly and mountainous regions were selected to verify the proposed methods.The assessment using both SRTM DEM andICESat-2 points shows that the DEM accuracy of auto-PS-GCP-Thin was improved by 20%∼30%for different areas compared to the manual,where the best DEM accuracy of 4.71 m was found in the plain area.It is concluded that the proposed methods are effective and reliable in various areas with different terrain conditions.
基金The Natural Science Foundation of China(No.40374003)
文摘Satellite differential synthetic aperture radar interferometry (DInSAR) has two limitations, i. e. , spatio-temporal decorrelation and atmospheric influence, for the application of regional deformation mapping. This paper proposed a new approach called time series DInSAR based on permanent scatters (PS) to overcome the limitations, and the relevant mathematical model and computing method are also developed. With the proposed algorithm, the experiments were performed to estimate the subsidence velocity field over Shanghai using 26 ERS-1/2 SAR images acquired from 1992 to 2002. The deformation signatures, atmospheric delay and other errors were separated effectively, and the subsidence velocity field over Shanghai was also derived.
文摘Considering the joint effects of various factors such as temporal baseline, spatial baseline, thermal noise, the difference of Doppler centroid frequency and the error of data processing on the interference correlation, an optimum selection method of common master images for ground deformation monitoring based on the permanent scatterer and differential SAR interferometry (PS-DInSAR) technique is proposed, in which the joint correlation coeficient is used as the evaluation function. The principle and realization method of PS-DInSAR technology is introduced, the factors affecting the DInSAR correlation are analysed, and the joint correlation function model and its solution are presented. Finally an experiment for the optimum selection of common master images is performed by using 25 SAR images over Shanghai taken by the ERS-1/2 as test data. The results indicate that the optimum selection method for PS-DInSAR common master images is effective and reliable.
基金supported by the National Natural Science Foundation of China[grant no 41790445]the Key Research and Development Program of Sichuan Province[grant no 2023YFS0439].
文摘Shanghai Pudong International Airport(PDIA),with its east side built along the coast with weak geological conditions,is prone to uneven foundation settlement due to the consolidation and compression of soil and erosion of coastal tides,affecting the safe operation of the airport.Therefore,it is crucial to conduct dynamic subsidence monitoring within the airport,especially in the runway area.29 scenes of ascending track Sentinel-1A radar images from August 2016 to June 2018 are selected to perform surface deformation inversion based on PS-InSAR and improved SBAS-InSAR for PDIA and its around coastal area.Through cross-validation,the reliability of the time-series InSAR technique for dynamic monitoring of surface deformation of coastal zone infrastructures is confirmed.The results show severely uneven settlement.By combining the monitoring results with the local geological and hydrological dataset,the driving factors of differential deformation of the infrastructures are analyzed,including stratigraphic geological conditions,ground loadings,foundation treatment methods,water erosion,and groundwater level changes.Finally,the time-series deformation characteristics and the causes of PDIA’s runway are emphasized based on the PS deformation results.This case provides a reference for the safety management of critical infrastructure in coastal areas using advanced InSAR technique.