Perbezaan antara semakan "Datum Tegak Amerika Utara 1988"

tiada ringkasan suntingan
(Mencipta laman baru dengan kandungan ''''Datum Tegak Amerika Utara 1988''' (NAVD 88) is the vertical control datum established for vertical control surveying in the [[United...')
 
The 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 tidal bench mark, referenced to the International Great Lakes Datum of 1985 local mean sea level height value, at [[Rimouski]], [[Quebec]], [[Canada]]. Additional tidal bench mark elevations were not used due to the demonstrated variations in sea surface topography, i.e., the fact that mean sea level is not the same equipotential surface at all tidal bench marks.
 
The NAVD 88 replaced themenggantikan [[NationalDatum GeodeticTegak VerticalGeodesi Datum ofNegara 1929]] ([[NGVD 29]]), previouslyyang knowndahulunya asdikenali thesebagai [[SeaDatum Level DatumAras ofLaut 1929]].
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== Lihat juga ==
* [[Altitud]]
* [[Datum Tegak AmerikaGeodesi UtaraNegara 1929]]
* [[Datum Aras Laut 1929]]
* [[Geodesi]]