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1. en.wikipedia.org › wiki › North_American_VerticalNorth American Vertical Datum of 1988 - Wikipedia

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   It superseded the National Geodetic Vertical Datum of 1929 (NGVD 29), previously known as the Sea Level Datum of 1929. NAVD 88, along with North American Datum of 1983 (NAD 83), is set to be replaced in 2025 with a new geometric reference frame and geopotential datum, based on GPS and gravimetric geoid models.

2. www.ngs.noaa.gov › datums › verticalNorth American Vertical Datum of 1988 (NAVD 88) - Vertical ...

   www.ngs.noaa.gov › datums › vertical

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   Jul 12, 2018 · The North American Vertical Datum of 1988 (NAVD 88) is the vertical control datum established in 1991 by the minimum-constraint adjustment of the Canadian-Mexican-United States leveling observations. It held fixed the height of the primary tidal bench mark, referenced to the new International Great Lakes Datum of 1985 local mean sea level ...

3. People also ask

   Does NAVD 88 mean sea level?

   • If the specific vertical datum is NAVD 88, areas outside North America can reference the sea level vertical datum or another local vertical datum. If the specific vertical datum is NGVD 29, areas outside the conterminous United States and Alaska can reference the sea level vertical datum. Can the term "mean sea level" be used?

   Guidance on Use and Documentation of Horizontal and Vertical Datum…

   www.usgs.gov/about/organization/science-support/office-science-quality-and-integrity/guidance-use-and

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   When did NAVD 88 become a vertical datum?

   • In 1993, NAVD 88 was affirmed as the official vertical datum in the NSRS for the Conterminous United States and Alaska (refer to the Federal Register Notice referenced below). For vertical datums applicable to U.S. territories, refer to the NGS vertical datums web page.

   Guidance on Use and Documentation of Horizontal and Vertical Datum…

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   What does NAVD 88 stand for?

   • The North American Vertical Datum of 1988 (NAVD 88) is based on an adjustment of leveling observations from across the country. A highly accurate surveying technique called geodetic leveling was used to measure height differences across the country. The 1988 vertical datum was based on over 600,000 kilometers of control leveling.

   Vertical Datum – Earth’s Elevation Reference Frame

   gisgeography.com/vertical-datum/

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   When was NAVD 88 renamed?

   • Therefore, it was renamed in 1973, the National Geodetic Vertical Datum on 1929. ( Geodetic Glossary, pp. 56) The North American Vertical Datum of 1988 (NAVD 88) is the vertical control datum established in 1991 by the minimum-constraint adjustment of the Canadian-Mexican-United States leveling observations.

   Frequently Asked Questions: Datums | Datums | National Geodetic Survey

   www.ngs.noaa.gov/datums/faq.shtml

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4. www.asce.org › publications-and-news › civilGetting the height right: The North American Vertical Datum ...

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   Nov 4, 2020 · HEIGHT DIFFERENCES BETWEEN NAVD 88 AND NGVD 29 IN CONTERMINOUS UNITED STATES; UNITS = CM (NOAA) According to the NGS website, surveyors used a method called Differential or Spirit Leveling, where a rod is held on a mark with a known elevation. “A reading is taken on the rod, which provides the elevation of the line-of-sight through the ...

5. vdatum.noaa.gov › docs › datumsNOAA/NOS's VDatum: A tutorial on datums

   vdatum.noaa.gov › docs › datums

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   Mean Sea Level based elevation are used for most construction and topographic surveys - in particular those involving flood control or shoreline improvement or shoreline protection. MLLW elevations are used in referencing coastal navigation projects.

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7. gisgeography.com › vertical-datumVertical Datum - Earth's Elevation Reference Frame - GIS ...

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   Oct 29, 2023 · These datums are used to measure the height (altitude) and depth (depression) above and below mean sea level. Commonly used vertical datums in North America are the National Geodetic Vertical Datum of 1929 (NGVD29) and the North American Vertical Datum of 1988 (NAVD88) .

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8. www.ngs.noaa.gov › datums › faqFrequently Asked Questions: Datums | Datums | National ...

   www.ngs.noaa.gov › datums › faq

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   Jul 12, 2018 · The datum is defined by the observed heights of mean sea level at the 26 tide gauges and by the set of elevations of all bench marks resulting from the adjustment. A total of 106,724 kilometers of leveling was involved, constituting 246 closed circuits and 25 circuits at sea level.

9. www.usgs.gov › about › organizationGuidance on Use and Documentation of Horizontal and Vertical ...

   www.usgs.gov › about › organization

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   For example, "The base of the model approximates the bottom of the high conductivity unconsolidated sediments (about 800 ft. above sea level)." If the specific vertical datum is NAVD 88, areas outside North America can reference the sea level vertical datum or another local vertical datum.