Schoolof Geographic and Biologic Information;
Nanjing University of Posts and Telecommunications;
Nanjing 210049;
China;
Beijing Key Laboratory of Urban Spatial Information Engineering;
Beijing 100038;
China;
State Key Laboratory of Informa-tion Engineering in Surveying;
Mapping and Remote Sensing;
Wuhan University;
Wuhan 430079;
China;
Department of Geoscience and Remote Sensing;
Delft University of Technology;
Delft 2628;
the Netherlands;
super resolution; persistent scatterer interferometry(PSI); positioning accuracy;