Using multiple RADARSAT InSAR pairs to estimate a full three-dimensional solution for glacial ice movement

Abstract

Multiple SAR interferograms are used to solve for the full 3-dimensional displacement of the surface of the Henrietta Nesmith Glacier in northern Ellesmere Island Canada. The approach exploits the incidence angle flexibility of different ascending and descending beam modes, and the azimuth angle diversity which occurs when different incidence angles are used at high latitudes. Line-of-sight displacements are estimated in 3 different orientations from the terrain corrected unwrapped differential phase and used to solve for the displacements in a local East, North, Up frame. Uncertainty in the absolute line-of-sight displacements limits the absolute accuracy for vertical displacement, however the relative solution coupled with knowledge of the surface slope allows spaceborne mapping of relative glacier thickening or thinning with unprecedented spatial resolution and with an accuracy of order a millimeter per day. Copyright 2011 by the American Geophysical Union.