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      • Using a fixed reference point as a baseline (i.e., a zero elevation point), elevation values can be consistently measured and compared among various maps and surveys. The North American Vertical Datum of 1988 (NAVD 88) is the official vertical datum of the United States, having superseded the older National Geodetic Vertical Datum of 1929 (NGVD 29).
      www.mass.gov/service-details/north-american-vertical-datum-of-1988-navd-88#:~:text=Using%20a%20fixed%20reference%20point%20as%20a%20baseline,National%20Geodetic%20Vertical%20Datum%20of%201929%20%28NGVD%2029%29.
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    What is the elevation of NAVD 88?

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  2. Understanding NAVD 88 and NGVD 29 Elevation Measurements ...

    www.foresitegroup.net/elevationmeasurements

    NAVD 88 is one of five current National Geodetic Datums, which are coordinate systems that act as standard reference lines to measure points on the earth’s surface in the region that they apply. A datum cannot be seen or physically measured because is a calculation of the Geoid/Mean Seal Level (MSL), which is the average global height of the ocean without any variables acting upon it, such as wind, climate, etc.

  3. North American Vertical Datum of 1988 - Wikipedia

    en.wikipedia.org/wiki/North_American_Vertical...

    The North American Vertical Datum of 1988 ( NAVD 88) is the vertical datum for orthometric heights established for vertical control surveying in the United States of America based upon the General Adjustment of the North American Datum of 1988. It superseded the National Geodetic Vertical Datum of 1929 (NGVD 29), previously known as the Sea Level Datum of 1929.

  4. North American Vertical Datum of 1988 (NAVD 88) | Mass.gov

    www.mass.gov/service-details/north-american...

    The North American Vertical Datum of 1988 (NAVD 88) is the official vertical datum of the United States, having superseded the older National Geodetic Vertical Datum of 1929 (NGVD 29). Both NAVD 88 and NGVD 29 are geodetic datums, a reference surface of zero elevation to which heights are referred to over a large geographic extent.

  5. Vertical Datum | South Florida Water Management District

    www.sfwmd.gov/science-data/vertical-datum

    Elevations determined using the North American Vertical Datum 88 (NAVD 88) standard are replacing measurements based on the National Geodetic Vertical Datum 29 (NGVD 29). The upgrade to NAVD 88 means that the values we associate with the height of water – what many people think of as mean sea level – will change.

  6. Flood Zone Maps

    www.broward.org/Environment/FloodZoneMaps/Pages/...

    A building finished floor elevation is shown on an existing elevation certificate as 10.0’ NGVD. The equivalent NAVD 88 elevation can be obtained using the FEMA-approved average conversion factor in the following formula: NAVD 88 = NGVD 29 + conversion factor NAVD 88 = 10.0’ NGVD + (-1.51)

  7. Guidance on Use and Documentation of Horizontal and Vertical ...

    www.usgs.gov/about/organization/science-support/...

    The product refers to an altitude or an elevation (orthometric height). State the vertical datum name and year in that document. Example: "Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88)."

  8. Vertical Datum Upgrade Frequently Asked Questions ...

    www.swfwmd.state.fl.us/resources/data-maps/...

    Within the boundaries of the District, the NAVD 88 elevation number is a shift of approximately 0.7 to 1.1 feet lower that the elevation in the NGVD 29 standard. This variation is due to geographical differences. For example, a water level for Lake Panasoffkee of 39.24 feet in NGVD 29 will be 38.36 in the NAVD 88 standard.

  9. North American Vertical Datum of 1988 (NAVD 88) - Vertical ...

    www.ngs.noaa.gov/datums/vertical/north-american...

    North American Vertical Datum of 1988 (NAVD 88) 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 height value, at Father Point/Rimouski, Quebec, Canada.

  10. NGVD Æ NAVD? - FEMA.gov

    www.fema.gov/.../ngvd_navd.pdf

    Jul 26, 2013 · NGVD 29 stands for National Geodetic Vertical Datum of 1929. It is a system that has been used by surveyors and engineers for most of the 20. th. Century. It has been the basis for relating ground and flood elevations, but it has been replaced by the more- accurate North American Vertical Datum of 1988 (NAVD 88).

  11. Gage Datum and Elevation - USGS

    waterdata.usgs.gov/wa/nwis/current/?type=datum

    The USGS in Washington State has used the National Geodetic Vertical Datum (NGVD) of 1929 as the datum for gages to determine elevation of gage-height data. Since the early 1990's the emphasis has been changing to use the new North American Vertical Datum (NAVD) of 1988, see a description of the differences between the two datums.