RE: OGC Ottawa TC meeting highlights

["Ron Lake" <rlake@xxxxxxxxxxxxx>]

Hi Roy:

I think the idea of a feature "varying over one of its coordinate axes"
is at best vague - since a feature in almost all cases does not have a
distinguished frame of reference (for the coordinate axes). If you wish
to think in this fashion, I think it would be better to think in terms
of a feature which has a property (or properties) whose value is a
distributed over the extent of the feature.   Consider for example a
road and its surface type. One might have a single property of the road
- surface that takes the values (paved, gravel, dirt) - and there is
only one such property for the entire road. At the other end of the
spectrum one might have a surface property whose value is a function
giving the distribution of the surface type as a function of distance
along the road. This distribution is a coverage and the value (in this
case) of the surface property.

Cheers

Ron

-----Original Message-----
From: owner-galeon@xxxxxxxxxxxxxxxx
[mailto:owner-galeon@xxxxxxxxxxxxxxxx] On Behalf Of Roy Mendelssohn
Sent: May 8, 2007 8:39 AM
To: Ben@xxxxxxxxxxxxxxxx
Cc: Unidata GALEON
Subject: Re: OGC Ottawa TC meeting highlights


On Apr 30, 2007, at 8:41 AM, Ben Domenico wrote:

>  The underlying unifying concept is that a "coverage" is in fact a  
> special case of a "feature" and ncML-GML and CSML dialects of GML  
> can provide the needed "wrapper."
>

I think this is backward.  I like the approach Simon Cox takes in the  
talk he gave at AGU last December, where a coverage is a feature that  
varies over one of its coordinate axes.  Thus a feature is a  
"collapsed" coverage, not the other way around.  If feature gets to  
be defined that broadly it loses all meaning.

-Roy
**********************
"The contents of this message do not reflect any position of the U.S.  
Government or NOAA."
**********************
Roy Mendelssohn
Supervisory Operations Research Analyst
NOAA/NMFS
Environmental Research Division	
Southwest Fisheries Science Center
1352 Lighthouse Avenue
Pacific Grove, CA 93950-2097

e-mail: Roy.Mendelssohn@xxxxxxxx (Note new e-mail address)
voice: (831)-648-9029
fax: (831)-648-8440
www: http://www.pfeg.noaa.gov/

"Old age and treachery will overcome youth and skill."



========================================================================
=======
To unsubscribe galeon, visit:
http://www.unidata.ucar.edu/mailing-list-delete-form.html
========================================================================
=======


===============================================================================
To unsubscribe galeon, visit:
http://www.unidata.ucar.edu/mailing-list-delete-form.html
===============================================================================