Re: [emergency] Groups - CRSRegistry Document by Galdos.doc uploaded

["Carl Reed" <creed@opengis.org>]

Allen -

Sorry for the delay in responding. Just returned from Asia and am in major
catch-up mode. Will respond in greater detail later.

Cheers

Carl

----- Original Message ----- 
From: "R. Allen Wyke" <allenwyke@mac.com>
To: <creed@opengis.org>
Cc: <emergency@lists.oasis-open.org>
Sent: Sunday, May 30, 2004 7:32 PM
Subject: Re: [emergency] Groups - CRSRegistry Document by Galdos.doc
uploaded


> Carl: apologize for just now getting back to this, but I needed to take
> some time to let some of the GIS-related comments and discussions that
> have been floating around to settle into my head. And while I admit, as
> I have done many times before, I am not GIS expert, I *think* I am able
> to understand the purpose and idea behind this document. As such, I had
> a question.
>
> In terms of how the Units of Measures are created, which if I
> understand correctly are used to create a given CRS, I am curious as to
> why these units (meter, degrees, etc.) where not defined as derived
> data types? It would seem that by having a UOM dictionary, which would
> be essentially a given CRS, that was nothing more than a list of these
> data types, one could simply reference, through Namespaces, that UOM
> dictionary in instance documents to therefore accomplish the same thing
> - rather than defining your own referencing scheme (srsName, codeSpace,
> etc.). Or, if the author of a given XML dialect, such as our authoring
> of CAP, wanted to explicitly specify which CRS' that were allowed, we
> would only need to import the applicable UOM dictionary(ies) to do
> that.
>
> Just wondering if I was misunderstanding something, as it seemed to me
> the same thing could be accomplished by simply using some of the
> features of XML Schema.
>
> Allen
>
> On Apr 10, 2004, at 4:42 PM, creed@opengis.org wrote:
>
> > The EM TC requested more information about how the OpenGIS Consortium
> > specifies coordinate reference systems (CRS). This request was in
> > relationship to CAP. This document provides basic information about
> > the prototype OGC CRS registry and how an application or encoding can
> > reference this registry.
>
>