Accuracy of three-dimensional glacier surface volocities derived from radar interfeometry and ice-soundin radar measurements

Johan Jacob Mohr, Niels Reeh, Søren Nørvang Madsen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

We present a method for analyzing the errors involved in measuring three-dimensional glacier velocities with interferometric radar. We address the surface-parallel flow assumption and an augmented approach with a flux-divergence (FD) term. The errors in an interferometric ERS-1/-2 satellite radar dataset with ascending- and descending-orbit data covering Storstrommen glacier, northeast Greenland, are assessed. The FD error assessment is carried out on airborne 60 MHz ice-sounding radar data from the same area. A simple model of an interferometric radar system is developed and analyzed. The error sources considered include phase noise, atmospheric distortions, baseline calibration errors, a dry snow layer, and the stationary-flow assumption used in differential interferometry. The additional error sources in the analysis of FD errors are noise, bias and unknown variations of the ice thickness, and approximations of the ice-flow model. The example glacier is now building up following a surge. The analysis shows that in the case study presented the errors are small enough to justify the use of both the estimated surface-parallel flow term of the vertical velocity and the estimated FD term of the vertical velocity.
Original languageEnglish
JournalJournal of Glaciology
Volume49
Issue number165
Pages (from-to)210-222
ISSN0022-1430
Publication statusPublished - 2003

Cite this