Abstract

Staying out of Trouble with Datum Transformations
Track: Geodesy & Geodetic Control
Author(s): Sam Knight

Datum transformation is an often misunderstood but critical step in converting data from one system to another. Unfortunately, it is also a step that can have a major effect on accuracy of the coordinate output. Transformation of a coordinate obviously changes the data, however, many transformation models appear similar at first glance even though they are quite different. The models vary in ways that can create a loss of accuracy if an inappropriate method is used. Choosing an appropriate transformation, both the method and the individual parameter set, is fundamental in maintaining the integrity of coordinate data. We will address common pitfalls in making the appropriate selections for datum transformations: Transformation methods and their parameters, the locally derived nature of individual transformations, and how to make a choice when there are multiple parameter sets for a given geographic area.

Sam Knight
Blue Marble Geographics
397 Water Street
Suite 100
Gardiner , Maine 04345
United States
Phone: 800-616-2725
Fax: 207-582-7001
E-mail: samk@bluemarblegeo.com