ICE VELOCITY ESTIMATION OF NARSSAP SERMIA IN GREENLAND USING MULTI-TEMPORAL X-BAND SAR OBSERVATIONS

摘要

Glaciers has been paid an attention as important indicator related to climate change and sea level rises from global wanning. In this study, we use multi-temporal X-band synthetic aperture radar (SAR) observations to analysis dramatic changes of ice velocity in glacier over Greenland. Differential radar interferometry' (DInSAR) can measure glacier movement with high accuracy of from cm to mm scale, but it is often limited by degraded loss of coherence due to significant temporal and volume decorrelation. Thus, we adopted intensity offset tracking to estimate the displacement of the different part of glacier. Since offset tracking is determined by the cross-correlation of the amplitude between two SAR images, it can be applied to large displacements regardless of temporal decorrelation. In this study, a time series of ice velocity of Narssap sermia and Qamanaarsuup Sermia was estimated by using TerraSAR-X/TanDEM-X X-band SAR images. We processed 95 SAR images, which were collected with mostly the 11-day temporal baseline in the stripmap mode at ascending direction, VV polarization, and incidence angle of 21.4 degree, acquired from July 22. 2013 to February 09. 2017. The multi-temporal observations of the ice velocity changes using available SAR data collected over about three and a half years will be presented. Estimated ice velocity time series would present seasonal and spatial velocity variations.