Global positioning system (GPS) data are now routinely used for many glaciological applications. In some common cases, systematic errors are unmodelled at the data-processing stage, although they are often presumed insignificant. In this paper, I investigate these assumptions for three different scenarios: (1) measurements on a moving glacier; (2) measurements on a floating ice shelf; and (3) precise height determination over large elevation ranges, such as for aircraft positioning in lidar/laser altimeter missions. In each case, systematic errors are shown to be present in the coordinate solutions that have a far greater magnitude than the formal error estimates produced by the GPS processing software, under certain conditions. If these coordinate biases go undetected, short- and long-term measurements of horizontal ice velocity or rates of ice-thickness change may be erroneous and the coordinates could not be expected to match rigorously processed data or results from different processing techniques. More rigorous processing strategies are discussed that allow for bias-free parameter estimation.

Item Type:	Refereed Article
Keywords:	data processing; glacier flow; GPS; parameterization
Research Division:	Earth Sciences
Research Group:	Physical Geography and Environmental Geoscience
Research Field:	Physical Geography and Environmental Geoscience not elsewhere classified
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Earth Sciences
UTAS Author:	King, MA (Professor Matt King)
ID Code:	81811
Year Published:	2004
Web of Science® Times Cited:	47
Deposited By:	Geography and Environmental Studies
Deposited On:	2013-01-08
Last Modified:	2013-01-08
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