[galeon] Fwd: CDM feature and point types docs

[Gerry Creager]

Ron, et al,

Ah, but then it becomes a science-discipline semantics issue, too.

I do think in terms of making "point" observations of in-situ weather 
data.  The observation is made at a fixed location, at a particular 
finite time, and its geometric property is not a bounded region or 
polygon, but a point.  Realizing there are gaps in this (wind is 
measured at 10m above ground, temperature, humidity, pressure at 2 
meters, precipitation at 1 meter, direct and diffuse solar radiation at 
nominally 2m but may vary, etc) the data are represented to end-users as 
being at a single spatial point.  Think of it as semantic collision 
rather than assimilation.

And, while I don't think I'm completely clueless, I've spoken at the 
TCs, and mentioned to you in the past, about "point features" in my use 
of WFS to represent observations, without discussion.

gerry

Ron Lake wrote:
> Hi all:
> 
>  
> 
> Just a quick comment.  I think the idea of a “point feature” is 
> misguided. The items covered in the list of point feature types is 
> better covered as an observation feature or observation event.  The 
> observation or observation collection then has geometric characteristics 
> such as where the observer was located, or where the observations are 
> located.  I am generally opposed to the idea of defining features by 
> their geometry properties since this has the semantics backwards.  No 
> instrument can make “point measurements” – so the items are observations 
> first and these observations then have geometric properties (like 
> location or estimated location).
> 
>  
> 
> Cheers
> 
> 
> Ron
> 
>  
> 
> *From:* galeon-bounces at unidata.ucar.edu 
> [mailto:galeon-bounces at unidata.ucar.edu] *On Behalf Of *Ben Domenico
> *Sent:* March 13, 2008 9:15 AM
> *To:* Unidata GALEON
> *Subject:* [galeon] Fwd: CDM feature and point types docs
> 
>  
> 
> Hi all,
> 
> Please note the DRAFT documents John Caron has created on CDM 
> data/feature types.  These are in the early stages of discussion and 
> revision so please keep in mind that this is all very much SUBJECT TO 
> CHANGE.   But the topics covered are important to GALEON so we need to 
> give them some thought.
> 
> -- Ben
> 
> ---------- Forwarded message ----------
> From: *John Caron* <caron at unidata.ucar.edu <mailto:caron at unidata.ucar.edu>>
> Date: Mon, Mar 10, 2008 at 1:19 PM
> Subject: CDM feature and point types docs
> To: techies <techies at unidata.ucar.edu <mailto:techies at unidata.ucar.edu>>
> 
> 
> new draft CDM Feature Types:
> 
> http://www.unidata.ucar.edu/software/netcdf-java/CDM/CDMfeatures.doc
> 
> new doc CDM Point Feature Types:
> 
> http://www.unidata.ucar.edu/software/netcdf-java/CDM/CDMpoints.doc
> 
> feedback appreciated
> 
>  
> 
> 
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> 
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-- 
Gerry Creager -- gerry.creager at tamu.edu
Texas Mesonet -- AATLT, Texas A&M University	
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