Talk:Datum (geodesy)

Geodetic datums
Not all datums are geodetic. Any measurement has an implied datum. 67.65.172.141 12:10, 2 August 2005

Here we go again "...which is almost identical to the NAD83 datum used in North America, is a common standard datum". There are other countries that use datums just like this one, but the sentence has no context in the article other than to drop a line about America again, which is getting a little ignorant of everyone else. 202.59.101.74 13:06, 6 April 2006 (UTC)


 * But this article is about geodetic datums:
 * This article describes a concept from surveying and geodesy.
 * Perhaps this title is too broad or ambiguous. 'Twould argue for merging this article's information into the geodetic system article and, if necessary, using this page for disambiguation links. -- Kbh3rd 17:20, 17 August 2005 (UTC)

I agree you can merge some portion of this to geodesy or surveying, but Datum can be more broadly defined using measurement examples or the datums in fluid mechanics.
 * I think the info here should indeed be merged to Geodetic system. This page could then have:
 * Datum is the singular form of data.
 * In navigation, geodetic datums are used to translate indicated positions on navigational tools to real earth positions.
 * Any thoughts? --AnOddName 22:30, 11 November 2005 (UTC)

Is there a good reason to try and merge Datum into the Geodetic system article? A Datum or Geodetic Datum is a specific concept that is well defined and a nice self-contained chunk of knowledge, that happens to be associated with other stuff, including geodetic systems, geodesy, projections, etc. I favor keeping this as a separate item. IMO merging too much into very large articles defeats the purpose of wikipedia, which is accessibility to logical chunks of knowledge. Tjamison 20:57, 14 March 2007 (UTC)

Vertical datums and chart datum
I've expanded the section on vertical datums, to include details on the various fluctuations that are smoothed out when calculating mean sea level, and an explanation of why nautical charts use other datums. I also removed the claim that Mean Lower Low Water is he usual chart datum. This appears to be true in US waters, but most charts from most other countries normally use Lowest Astronomical Tide. (The chart datum page could probably be expanded to include a more detailed discussion of what datums are used and why and by whom). Wardog 14:38, 23 September 2007 (UTC)

Datums?
OED has no record of the word datums. In the entry for datum, it is uniformly pluralised to data. It might be handy to provide some sources for this novel coinage. PRB (talk) 08:23, 14 April 2010 (UTC)


 * Google has over 10,000,000 hits for "datums", which makes it common usage—it is certainly not novel. — Joe Kress (talk) 06:07, 17 April 2010 (UTC)


 * Both Webster's Third New International Dictionary and the Random House Dictionary of the English Language give datums as the plural in surveying and related fields. Thus the OED is deficient. — Joe Kress (talk) 03:34, 18 April 2010 (UTC)


 * Because both Webster's Third and Random House are American unabridged dictionaries whereas the OED is British, I suspected a possible geographic bias, but both A guide to coordinate systems in Great Britain written by Great Britain's Ordnance Survey and a United Kingdom National Maritime Museum page use "datums" throughout, still indicating a deficient OED regarding this word. — Joe Kress (talk) 21:24, 18 April 2010 (UTC)


 * Do any surveying sources use "data"? The article is rather dogmatic that "data" is wrong. Tesspub (talk) 21:34, 18 October 2011 (UTC)