Abstract

Achieving Great Heights: A New Vertical Datum for the U.S.
Track: Surveying
Authors: Mark Eckl

The world is a dynamic environment that is ever changing and NOAA's National Geodetic Survey (NGS) is working towards a reference systems to better define elevation. The North American Vertical Datum of 1988 (NAVD 88) provided a good reference based on the best theory and technology of the day. We are continuously learning more about the effects of such things as glacial rebound, oil and water extraction subsidence and vertical effects from plate tectonics. A better understanding of the geophysics of the Earth and an evolution of positioning and remote sensing technology is driving our countries' need to replace NAVD 88. This presentation focuses on how NGS is working to define a new vertical reference system that builds on a better understanding of the earth and is compatible with current/future technology (Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project). Doing so provides continuity throughout cartographic products.