(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.
== Lihat juga ==
* [[Datum Tegak
* [[Datum Aras Laut 1929]]