Precise Monitoring of Active Volcanoes using Space-borne L- and C-band Polarimetric SAR Systems
Wooil M. Moon(1,4), Sang-Wan Kim(2) and Duk-Jin Kim(3)
(1) The University of Manitoba, Satellite Geophysics, Winnipeg, MB R3T 2N2, Canada
(2) Sejong University, Department of Geoinformation Engineering, Seoul 143-747, Korea
(3) Seoul National University, School of Earth and Environmental Studies (SEES), Seoul 151-742, Korea
(4) Seoul National University, 4. Research Institute of Oceanography (RIO), SEES, Seoul 151-742, Korea
Monitoring and studying of active volcanoes is a complex process which can be approached from various disciplines. In this study, Mt. Baekdu-san (N. Korea) and Mt. Hekla (Iceland) strato-volcanoes are monitored with D-InSAR technique utilizing available space-borne SAR systems, including the JERS-1 SAR (L-band, HH pol) (1992-1998), ALOS PALSAR (L-band, Dual pol) (2007- ), ERS-1/2 (C-band, VV pol) (1992-2002), and now the new RADARSAT-2 (C-band, Dual pol) (2008- ). Both Mt. Baekdu-san and Mt. Hekla are moderately active strato-volcanoes in the tectonic intraplate and mid-Atlantic tectonic spreading center, respectively.
Accurate and precise monitoring of surface displacements of a volcano with InSAR techniques requires accurate DEM, optimum baseline configuration for each pair of SAR data, and various accurate auxiliary data such as upper atmospheric anomalies in the study area. Preliminary results of D-InSAR study of these two volcanoes show that one can measure the surface displacements up to sub-centimeter accuracy with L-band HH pol repeat pass data when properly processed. The monitoring and investigation of these two volcanoes is continuing with the ALOS PALSAR (L-band) Dual pol data as well as the new RADARSAT-2 (C-band) Dual pol data.
Volcanic activity is a continuing process in both temporal and spatial space and the Earth orbiting platform provides the optimum opportunity for natural disaster monitoring. More recently severe volcano activities at Mt. Baekdu-san have been reported. The 9 year and 6 year gaps in the L-band and C-band respectively provide additional challenges in D-InSAR observation of these two volcanoes. This study has thus aimed to monitor these two volcanoes, Mt. Baekdu-san and Mt. Hekla, in two frequencies, L-band and C-band, in a continuous fashion with objectives of investigating the dynamic aspects of volcanic activities as well as monitoring and mitigation of volcanic threats in the nearby human settlements of the active volcanic centers.