We combine conventional Interferometric Synthetic Aperture Radar (InSAR) and Multiple Aperture InSAR (MAI) to determine the ice surface velocity on the Langjokull and Hofsjokull ice caps in Iceland in 1994. This approach allows the velocity of the 20 principal ice cap outlet glaciers to be fully resolved. We show that MAI leads to displacement estimates of finer resolution (15 versus 150. m) and superior precision (5 versus 15. cm) to those afforded by the alternative technique of speckle tracking. Using SAR data acquired in ascending and descending orbits, we show that ice flows within 15° of the direction of maximum surface slope across 66% of the ice caps. It is therefore possible to determine ice displacement over the majority of the ice caps using a single SAR image pair, thereby reducing errors associated with temporal fluctuations in ice flow.
|Number of pages||5|
|Journal||Earth and Planetary Science Letters|
|Publication status||Published - 1 Jul 2011|
Bibliographical noteFunding Information:
This work was supported by award from the European Space Agency Changing Earth Science Network program (N.G.), by award from the Basic Science Research Program of the National Research Foundation of Korea (NRF) and the Ministry of Education, Science and Technology (No. 2010-0028025 ) (S.W.K.) and by award from the UK Natural Environment Research Council Antarctic Funding Initiative ( NE/E014089/1 ) and a Philip Leverhulme Prize (A.S.). The dataset was provided by the European Space Agency through the VECTRA consortium. Part of the SAR data processing has been performed using the freely available JPL code ROI_PAC. We thank Hyung-Sup Jung and Steven J. Palmer for their help and support, and two anonymous reviewers for comments that helped improve the manuscript.
- Ice velocity
- Multiple Aperture InSAR