Abstract

Positioning America for the future: New Geometric Datum for U.S.
Track: Surveying
Authors: Joe Evjen

Advances in satellite geodesy have improved survey accuracies and provided new insights into our dynamic world, while revealing problems with the official reference frame used to measure them. The North American Datum of 1983 (NAD 83) should be replaced by a more truly geocentric reference frame that accounts for tectonic plate motion. The National Geodetic Survey (NGS) will discuss the history of and modifications to NAD 83, residual plate velocities, misalignment to the International Terrestrial Reference Frame (ITRF), how a new reference frame can address these issues and provide new benefits, and offer suggestions to users that will be affected.