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Datums...
From: Aubrey O?Callaghan
Date: 2004 Sep 23, 09:18 +0100
From: Aubrey O?Callaghan
Date: 2004 Sep 23, 09:18 +0100
I received an interesting technical question on our internal bulletin
board today asking about a datum NAP specifically in the
Netherlands.
Being interested in navigation I did a little digging, and want to share my fiindings with the group.
A google search of NAP and datum brings up
NORMAAL AMSTERDAMS PEIL, this translates as Amsterdam Ordnance Datum. This water level was recognized over three centuries ago as the referral point for all constructions in the Netherlands and several adjoining countries. (http://www.hiptravelguide.com/amsterdam/php/article-132.html). This is a land datum.
The following URL www.geo.tudelft.nl/fmr/deosletter/98-1/art7.pdf has a nice introduction. "The land height datum NAP refers to the MSL at the
time of definition, and in a strict sense the NAP heights do not refer to an equipotential anymore, due to land subsidence and sea level change."
Probably for our purposes we can consider NAP and MSL to be equivalent -but I would stand corrected by someone more knowledgeable.
By the way I think that the plural of datum is data... George ?
Aubrey.
Being interested in navigation I did a little digging, and want to share my fiindings with the group.
A google search of NAP and datum brings up
NORMAAL AMSTERDAMS PEIL, this translates as Amsterdam Ordnance Datum. This water level was recognized over three centuries ago as the referral point for all constructions in the Netherlands and several adjoining countries. (http://www.hiptravelguide.com/amsterdam/php/article-132.html). This is a land datum.
The following URL www.geo.tudelft.nl/fmr/deosletter/98-1/art7.pdf has a nice introduction. "The land height datum NAP refers to the MSL at the
time of definition, and in a strict sense the NAP heights do not refer to an equipotential anymore, due to land subsidence and sea level change."
Probably for our purposes we can consider NAP and MSL to be equivalent -but I would stand corrected by someone more knowledgeable.
By the way I think that the plural of datum is data... George ?
Aubrey.
Good morning,
Could anybody explain to me the difference between depth referenced to MSL and depth referenced to NAP?
This for operations in the nederlands.
I would like to know if the diference between the two reference is a constant, what is the value in that case ?
