NGS Releases New Geoid Model to Serve Surveying, Engineering, and Scientific Communities
In the last week, the National Geodetic Survey has released a new height transformation model for surveyors, engineers, and the scientific community involved in water flow and the determination of heights with respect to mean sea level.
The new "GEOID12" model, implemented in Global Navigation Satellite System (GNSS)-manufacturer software, provides transformations of centimeter-level accuracy from GNSS-derived heights to North American Vertical Datum of 1988 () orthometric elevations.
GEOID12 is a refined hybrid model of the geoid in the United States and other territories
This model is intended for converting between the NAD83 ellipsoid reference frame resulting from the National Adjustment of 2011 and vertical datums NAVD88, GUVD04, ASVD02, NMVD03, PRVD02 and VIVD09. See the FAQ page for datum details.
For GEOID12 in CONUS regions, heights range from a low of -50.71 meters (magenta) in the Atlantic Ocean to a high of 3.31 meters (red) in the Labrador Strait. However, these geoid heights are only reliable within CONUS due to the limited extents of the data used to compute it. See link to GPS On Bench Marks Used To Make GEOID12 to the right.
You can learn more here »»GEOID12