GIS Dictionary
Definitions for GIS terms related to operations such as analysis, GIS modeling and web-based GIS, cartography, and Esri software.
Now available for purchase: A to Z GIS: An illustrated dictionary of geographic information systems.
Search the GIS Dictionary:
GIS Bibliography
Researching GIS?
Search the GIS Bibliography for a vast index of books, journals, conference proceedings and reports.
plumb line
-
[surveying]
A line that corresponds to the direction of gravity at a point on the earth's surface; the line along which an object will fall when dropped.