GD3-4 - Linear referencing systems

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Author and Citation Info: 

DiBiase, D., DeMers, M., Johnson, A., Kemp, K., Luck, A. T., Plewe, B., and Wentz, E. (2006). Linear referencing systems. The Geographic Information Science & Technology Body of Knowledge. Washington, DC: Association of American Geographers. (2nd Quarter 2016, first digital).

Learning Objectives: 
  • Describe an application in which a linear referencing system is particularly useful
  • Explain how the datum associated with a linear referencing system differs from a horizontal or vertical datum
  • Identify several different linear referencing methods (e.g., mileposts, reference posts, link and node) and compare them to planar grid systems
  • Identify the characteristics that all linear referencing systems have in common Unit GD4 Datums (core unit) “Horizontal” datums define the geometric relationship between a coordinate system grid and the Earth’s surface, where the Earth’s surface is approximated by an ellipsoid or other figure. “Vertical” datums are elevation reference surfaces, such as mean sea level.
  • Explain how a network can be used as the basis for reference as opposed to the more common rectangular coordinate systems
  • Discuss the magnitude and cause of error generated in the transformation from linear to planar coordinate systems