NGS Initiatives NGS Initiatives[ Height Modernization | New Reference System ]
Height Modernization is a series of activities designed
to advance and promote the determination of
elevations by GPS surveying, rather than by spirit
leveling. It includes research and development
activities seeking to improve the determination of
geometric elevations by GPS surveys as well as
activities seeking to improve the determination of
geoid height. It includes activities leading to improved
height determination both for the static surveyor and
for the moving navigator.
The series of GPS surveys called High
Accuracy Reference Networks (HARNs)
were completed in 1998. These surveys
were carried out on a state by state
basis, leading to some inconsistencies at the
borders between states. The availability of
all this high accuracy data suggests that
the time is right for a new simultaneous continental adjustment. Should this
adjustment be a slight improvement of NAD 83 coordinates or should it be
based on the more modern International Terrestrial Reference System? Should it
include only the GPS stations or all stations in the NGS data base?
Created by Charlie Schwarz
Friday, 13-Aug-2004 15:42:10 EDT
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