Talk:Military Grid Reference System

Maps B‑class High‑importance

	This article is within the scope of WikiProject Maps, a collaborative effort to improve the coverage of Maps and Cartography on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.MapsWikipedia:WikiProject MapsTemplate:WikiProject MapsMaps
B	This article has been rated as B-class on Wikipedia's content assessment scale.
High	This article has been rated as High-importance on the project's importance scale.
	This article has been automatically rated by a bot or other tool because one or more other projects use this class. Please ensure the assessment is correct before removing the `\|auto=` parameter.
	This article had an importance automatically assigned to it. Once it has been checked by a human, please remove `\|autoi=yes`.

Military history: Technology B‑class

This article is within the scope of the Military history WikiProject. If you would like to participate, please visit the project page, where you can join the project and see a list of open tasks. To use this banner, please see the full instructions.Military historyWikipedia:WikiProject Military historyTemplate:WikiProject Military historymilitary history

B

This article has been rated as B-class on the project's quality scale.

This article has been checked against the following criteria for B-class status:
Referencing and citation: criterion met Coverage and accuracy: criterion met Structure: criterion met Grammar and style: criterion met Supporting materials: criterion met

Associated task forces:
/
	Military science, technology, and theory task force

This needs to be categorized.

Georef?

Anyone heard of Georef? When I was in the Royal Observer Corps, many years ago, I remember we used "UTM" on some maps, which seems to be the Military grid reference system; co-ordinates (within Europe, say) were like "PQ 123 456". But on other maps, we used a system I remember being called "Georef". This had a similar notation — two letters to identify a major "square", then two or more digits to identify a point within the "square" — but was based on lat-long, not UTM; hence, the "squares" were curved-trapezoids. You got the accuracy of lat-long with the convenient notation of UTM / British grid. Now I can't find any info on Georef (which, if it really existed, sureley deserves a mention). Anyone ever heard of this? — Johantheghost 18:10, 2 December 2005 (UTC)[reply]

OK, to reply to myself, I found some info, and we now have an article on Georef. — Johan the Ghost _seance 11:21, 17 February 2006 (UTC)[reply]

What datum?

This makes no sense whatsoever. Anyone care to explain? How does someone have a legitimate lat and long and not know where on earth it is?! RobertDahlstrom (talk) 21:49, 7 May 2008 (UTC)[reply]

Such an MGRS coordinate, standing alone, may be converted to latitude and longitude. But you still do not know the position on the Earth, unless you also know the geodetic datum that is used.

Sorry about being too brief, but I hoped people would follow the link to geodetic datum. Actually, a better link would be A guide to coordinate systems in Great Britain, published by the Ordnance Survey. It gives the best explanation of geodetic datums that I have ever seen. Figure 1 in the introduction gives an example of what I meant. --Mikael R (talk) 19:14, 13 May 2008 (UTC)[reply]

I too am confused about why a different coordinate system cannot indicate the same location. Seems to me (an ignorant layman) that it would depend instead on whether they use the same datum. Or is there a rule that says that's not allowed? Jim.henderson (talk) 01:56, 18 January 2011 (UTC)[reply]

I don't see how the statement is relevant to MGRS. Yes it's true that lat/lon requires a datum in order to be properly interpreted, but this article is about MGRS, not lat/lon. The rest of the article is focused on MGRS-specific traits, but this sentence about lat/lon is an entry to a whole other set of topics, and I think it's distracting here. It's like it's there just to lead you off into datums and geodesy, etc. Pardon my snarky example, but it would be like me saying that you can enter an MGRS coordinate into a handheld GPS unit, but the GPS won't work without batteries. i.e., not relevant to MGRS. -- LVB (talk) 17:09, 28 June 2013 (UTC)[reply]

point reference system

I see no link to "point reference system" nor article by that name. Is the concept explained in another article, or should the distinction between that and other systems be explained in this one? Jim.henderson (talk) 09:29, 16 January 2011 (UTC)[reply]