Dual-band Radar Interferometry

This paper demonstrates the feasibility of using differential interferometric synthetic aperture radar (DInSAR) for subsidence monitoring over the underground mining sites in New South Wales, Australia. The SAR data acquired in dual-frequency, Cand L-band, of microwave portion of electromagnetic spectrum by ERS-1/2, Radarsat-1 and JERS-1 satellites have been examined. The issues of decorrelation and high phase gradient in the interferometric phase have been addressed. The results of ERS-1/2 tandem interferometry show high conservation of coherence for the two acquisitions with 1 day interval. In contrast, repeat-pass interferometry results with the temporal baselines at the multiples of 24, 35, and 44 days for Radarsat-1, ERS-1/2, and JERS-1, respectively, show the degradation significantly greater than the tandem case due to the much larger temporal baselines. However, Radarsat-1 fine beam mode data show the decorrelation can be reduced using finer imaging resolution. In order to overcome the high phase gradient, either shorter revisit period of the satellite or longer wavelength of the microwave need to be used. The possibility of determining the displacement vectors in 3D is also discussed in this paper. BIOGRAPHY OF PRESENTER Dr Linlin Ge is currently a Senior Lecturer of remote sensing and GPS at the University of New South Wales (UNSW). He received his BEng (1st Hons) in Optical Engineering from the Wuhan Technical University of Surveying and Mapping (1985), MSc in Crustal Deformation from the Institute of Seismology (1988), and PhD in GPS and remote sensing from the UNSW (2001). His current research interests include microwave and optical remote sensing, structural deformation monitoring, kinematic interpretation of CGPS data (the so-called “GPS seismometers”), interpretation of CGPS data by incorporating synthetic aperture radar interferometry (InSAR), mitigation of atmospheric disturbance in InSAR, and analysis of single-frequency GPS observations with the aid of dual-frequency GPS data.