Experimental study on detecting crustal deformation using C-band SAR interferometry in the Japanese Islands

The current space-borne C-band ERS-1/SAR and RADARSAT-I data were processed and analyzed experimentally for extracting interferometric fringe. Then the possibility for detecting crustal deformation in several Japanese test sites is discussed. As the result of interferometric analysis of ERS-1/SAR data, baseline distance should be short for generating initial interferogram. It is found that the fringe continuity and coherence are significantly affected by not only observation interval but also land cover conditions. That proves that C-band SAR interferometry are more sensitive to ground surface stability than L-band SAR. According to this sensitivity, damaged urban areas by Hyogoken-nanbu earthquake could be detected. Local phase difference change patterns are found from the multi data pairs which interval included the earthquake. The data pair observed in the eastern part of Saitama prefecture with 933 days interval also indicates local fringe patterns which correspond with precise leveling results. As the result of interferometric analysis for RADARSAT-I data, the conditions for extracting continuous fringe are estimated to be similar to that of ERS-1/SAR data. Although the selection of test sites and data pair are important to generate continuous fringe, C-band SAR interferometry is expected to estimate local deformation in urban area.