Hi, I'm Rachael Dempsey, NOS deputy assistant
administrator for navigations, observations, and positioning.
Scientists at NOAA's National Geodetic Survey
have completed the first major phase in a pioneering
16 year project to improve elevations for the nation.
The first phase of the Gravity
for the Redefinition of the Vertical Datum Project,
also known as GRAV-D,
measured the gravity field from aircraft over the entire nation,
including the continental U.S.,
Alaska, Hawaii and all U.S. territories.
Elevation data from the current vertical datum
has elevation errors ranging from 16 inches to six feet.
With GRAV-D data, the modernized national spatial reference system
elevations will be accurate to less than an inch in most areas.
That's at least a 20 times increase in accuracy.
These improved elevations
from the GRAV-D project will help reduce risk
for coastal communities through better flood predictions
associated with storms and tsunamis
and support better emergency evacuation planning.
More accurate elevation data benefit
infrastructure planners and precision agriculture,
as we can better predict
where water will pool and flow.
This project will further contribute
to the modernization
of the nation's coordinate system,
the National Spatial Reference System.
This consistent coordinate system defines latitude,
longitude, height, scale, gravity, orientation and shoreline
throughout the United States.
Learn more about this important work
and NOAA's critical role of providing the framework
for all positioning activities in the nation
by visiting the link in this post.