HR: 1340h
AN: H23D-1151    [Abstracts]
TI: Comparative Image Analysis to Ensure Data Quality in the Global Land Ice Measurements from Space (GLIMS) Glacier Database
AU: * Raup, B H
EM: braup@nsidc.org
AF: National Snow and Ice Data Center, 449 UCB, University of Colorado, Boulder, CO 80309-0449 United States
AU: Khalsa, S S
EM: sjsk@nsidc.org
AF: National Snow and Ice Data Center, 449 UCB, University of Colorado, Boulder, CO 80309-0449 United States
AU: Armstrong, R
EM: rlax@nsidc.org
AF: National Snow and Ice Data Center, 449 UCB, University of Colorado, Boulder, CO 80309-0449 United States
AU: Cawkwell, F
EM: fiona.cawkwell@ualberta.ca
AF: University of Alberta, Department of Earth and Atmospheric Sciences, Edmonton, AB T6G 2E3 Canada
AU: Georges, C
EM: Christian.Georges@uibk.ac.at
AF: University of Innsbruck, Department of Geography Am Innrain 52, Innsbruck, A-6020 Austria
AU: Hamilton, G
EM: gordon.hamilton@maine.edu
AF: University of Maine, Climate Studies Center 303 Global Sciences, Orono, ME 04469-5790 United States
AU: Sneed, W
EM: william.sneedjr@maine.edu
AF: University of Maine, Climate Studies Center 303 Global Sciences, Orono, ME 04469-5790 United States
AU: Wheate, R
EM: wheate@unbc.ca
AF: University of Northern British Columbia, 3333 University Way, Prince George, BC V2N 4Z9 Canada
AB: GLIMS (Global Land Ice Measurements from Space) is an international collaborative project to map the world's glaciers and to build a GIS database that is usable via the World Wide Web. The GLIMS programme includes approximately 60 institutions, divided into twenty Regional Centers (RCs), who analyze satellite imagery, primarily ASTER and Landsat, to map glaciers in their regions. The results are collected at the National Snow and Ice Data Center (NSIDC) and inserted into the GLIMS Glacier Database. A major concern for future users of the database is data quality. The process of analyzing imagery to extract vector outlines of glaciers has been automated to some degree, but human expertise remains essential to the process. To quantify the consistency of data provided by different Regional Centers, we carried out a method of comparative image analysis whereby several RCs analyzed the same group of glaciers in one image. The image was chosen to contain a variety of glaciers, as well as several glacier boundary types: ice-water, ice-rock, snow-rock, snow-snow. The results, in the form of glacier outlines, were compiled, compared, and quantified for consistency. We will describe the results of this experiment, which uncovered a variety of errors that may occur during the analysis. As a result, GLIMS is instituting a series of protocols that Regional Centers must follow in order to produce glacier data for GLIMS.
UR: http://www.glims.org/
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
DE: 1640 Remote sensing
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting