GEOID09 is a refined hybrid model of the geoid in the United States and other territories, which supersedes the previous models GEOID06, GEOID03, GEOID99, GEOID96, GEOID93, and GEOID90.
This model is intended for converting between the NAD83 ellipsoid reference frame and vertical datums NAVD88, GUVD04, ASVD02, NMVD03, PRVD02 and VIVD09. See the FAQ page for datum details.
For GEOID09 in CONUS regions, heights range from a low of -50.68 meters (magenta) in the Atlantic Ocean to a high of 3.44 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.
UPDATE: The GEOID09 model for the combined Puerto Rico and U.S. Virgin Islands region has now been released. Note that the model is built on the GPS on BM data given in the link to the lower right for that region. Due to a likely 20 cm offset at the St. Croix tide gauge, a 20 cm offset is incorporated into the GEOID09 model surrounding St. Croix. Also look for GEOID12 in the near future to include release for this region with the rest of the models.
For reference only, model GEOID09BETA is available
