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- A fixed base elevation at a tide station to which all water level measurements are referred. The datum is unique to each station and is established at a lower elevation than the water is ever expected to reach.
tidesandcurrents.noaa.gov › datum_options
People also ask
Does NAVD 88 mean sea level?
When did NAVD 88 become a vertical datum?
What is a datum of sea level?
When was the national geodetic vertical datum renamed?
Neither NAVD 88 nor NGVD 29 are in conformance with mean sea level, nor with the geopotential surface that best fits the Earth’s mean sea surface (idealized global geoid). NAVD 88 is a better realization of an orthometric datum based on a geopotential surface; however that geopotential is not the ideal global geoid.
NAVD 88 was established in 1991 by the minimum-constraint adjustment of geodetic leveling observations in Canada, the United States, and Mexico. It held fixed the height of the primary tide gauge benchmark, referenced to the International Great Lakes Datum of 1985 local mean sea level (MSL) height value, at Rimouski, Quebec, Canada.
Nov 4, 2020 · The NAVD 88 used some of the original data from 1929 but also re-leveled about 100,000 km. Originally scheduled to be completed in 1988, it was finished on June 15, 1991. The new datum produced fewer distortions than earlier vertical datums and more accurate elevations, according to Remondi.
Use of the term "sea level" as a synonym for NGVD 29 in USGS publication series information products is discontinued. However, Mean Sea Level (MSL), a tidal datum that pertains to local mean sea level, should not be confused with or substituted for the fixed datums of NGVD 29 or NAVD 88.
However when Sea Level Datum of 1929 (MSL) and was superseded by the NGVD 29 the numbers didn't change; it was a name change only. So, the 29 ft lake elevation the CoE referenced is NGVD 29. To convert to NGVD 29 to NAVD 88 you simply add 3.6 feet. So the 29 ft lake elevation (MSL or NGVD 29) is 32.6 ft NAVD 88.
