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North American Vertical Datum (NAVD) 1988 (VDT_4)

DGIF baseline 2026-1, the latest. Earlier baselines: timemap.

Name: navd88
Attribute: VDT Vertical Datum
Definition: A fixed reference for elevations derived from a general adjustment of the first-order terrestrial levelling nets of the United States, Canada, and Mexico.
Description: In the adjustment, only the height of the primary tidal bench mark, referenced to the International Great Lakes Datum of 1985 local mean sea level height value, at Pointe-au-Pere, Quebec, on the Gulf of St. Lawrence was held fixed, thus providing minimum constraint.
Accepted: 2013-10-18
Defined by: DFDD BL2013-1.00