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Online GIS Glossaries
ESRI - The GIS Glossary:
http://www.esri.com/library/glossary/glossary.html
Association for Geographic Information:
http://www.agi.org.uk/
Canada Centre for Remote sensing Glossary: http://www.ccrs.nrcan.gc.ca/ccrs/homepg.pl?e
ERDAS Glossary: http://www.erdas.com/
ERDAS Glossary in PDF- Format: http://www.uni-kiel.de/castle/glossary/glossary.pdf