Analysis of Capabilities of C-and L-band SAR Data to Detect Newly-reclaimed Area

Time series interferometric synthetic aperture radar (InSAR) technology is employed to process two stacks of C-band ENVISAT ASAR and L-band ALOS PALSAR data to retrieve the settlement velocity field from 2007 to 2010 in the Lingang area located in southeast Shanghai. About forty-five percent of the total land in the Lingang area was created by reclamation projects. Land subsidence has become a significant issue as un-compacted filling materials cover unconsolidated marine sediments. Our study revealed that significant subsidence caused by hydraulic fill consolidation exists within Lingang; the settlement velocity can be as high as -30 mm/a, which implies the necessity for long-term continuous monitoring. The results from C-and L-band data were analyzed and compared in terms of precision regarding leveling data, the density of coherence points and time dimension. The L-band results show some advantages in the developing area while C-band results provide relative precise measurements.