The second edition of this text on principles of geographic information systems (GIS) covers GIS design and modelling, reflecting the author's belief that modelling and analysis are at the heart of GIS. This enables students to understand how to use a GIS and what it does. The addition of over 35 new graphics presents concepts simply, without extraneous material, while visual and analytical errors to existing graphics have been corrected. New sections have been added on datums, neighbourhood functions, and shapefiles. Sections on scanning and measuring linear distance have been updated.