A review on the application of Interferometric Synthetic Aperture Radar on surface deformation monitoring
ZHANG Shuan-hong~1, JI Zhan-sheng~2 (1.Institute of Geomechanics,CAGS,Beijing\ 100081,China; 2.Institute of Geology,CAGS,Beijing\ 100037,China)
In recent years, the techniques of Interferometric Synthetic Aperture Radar(InSAR) and differential Interferometric Synthetic Aperture Radar(D-InSAR) have been widely used in surface deformation monitoring, which achieved much attention from many earth scientists. New results on surface deformation surveys from different places show that the techniques of InSAR and D-InSAR have great potential in detecting displacements caused by earthquake deformation, glacier movement, neotectonics, ground subsidence and landslides. Some of the results can't be achieved by other methods.Compared with the conventional approaches(such as GPS monitoring), using of InSAR and D-InSAR in surface deformation monitoring has many advantages. First, the InSAR images can cover a large area on the earth, and the result can be obtained in a relatively short time. Second, there is no need to establish the monitoring network; so the cost is low. Third, the spatial resolution is high and the continue displacement information of the ground can be achieved theoretically. Fourth, the potential or unknown ground displacement can be identified, which is very useful for the rural area or the dangerous places where we can't easily arrive. Finally,because the cloud and the light have no effect on the Synthetic Aperture Radar images, the images can be obtained every times when the SAR satellites pass the area. But the application and accuracy will be influenced because of some inherent factors of InSAR and variations of ground plant, humidity and atmosphere at different time. So the InSAR and D-InSAR approaches should be improved and combined with geological study and other methods.In order to improve the accuracy of InSAR and D-InSAR in monitoring the surface deformation, a new technique, known as the Permanent Scatterers(PS) approach, has been developed recently. By selecting isolated points on the ground which exhibit extremely stable interferometric phase behavior over time, the new approach overcomes most of the resolution, tempeoral and spatial baseline limitations hindering conventional InSAR processing, which has greatly improved the accuracy of InSAR to ground deformation monitoring, especially in the cities or the places where the rocks are well exposed. With the introduction of the PS approach, sometimes the ground displacement can be measured to millimetric accuracy.
【CateGory Index】： P642