[Auscope-geosciml] CGI Value abomination [SEC=UNCLASSIFIED]

Simon Cox simon.cox at jrc.ec.europa.eu
Wed Sep 2 12:26:26 EDT 2009


I was responding to John's mail, where he appeared to be saying 'some fields
will never be interoperable' (because of institutional reasons). If we
really think they aren't (and he may have a point here), then there is zero
benefit and only cost in forcing a data provider to coerce their
non-ineroperable data into complex structures. 

Eric brought up SWE Common as a (more broadly accepted) alternative, though
he pointed out that in practice SWE Common is as permissive as CGI_Value
(but probably has more code to support it - though I think it is only
maintained by one person (Alex Robin) who does not keep his documentation
up-to-date). 

If there is interest in looking at SWE Common as a replacement (I agree that
it probably has more momentum, and Alex is very diligent in publicizing it),
but are concerned about the absence of _qualifiers_ (or anything else in
fact) then can I suggest that this requirement is URGENTLY brought to the
SWE Common v2.0 revision working group in OGC - they are actively working on
v2.0, and my guess is it will be wrapped up in a matter of months. 


--------------------------------------------------------
Simon Cox

European Commission, Joint Research Centre, 
Institute for Environment and Sustainability, 
Spatial Data Infrastructures Unit, TP 262 
Via E. Fermi, 2749, I-21027 Ispra (VA), Italy 
Tel: +39 0332 78 3652
Fax: +39 0332 78 6325
mailto:simon.cox at jrc.ec.europa.eu 
http://ies.jrc.ec.europa.eu/simon-cox 

SDI Unit: http://sdi.jrc.ec.europa.eu/ 
IES Institute: http://ies.jrc.ec.europa.eu/
JRC: http://www.jrc.ec.europa.eu/
--------------------------------------------------------

-----Original Message-----
From: auscope-geosciml-bounces at lists.arcs.org.au
[mailto:auscope-geosciml-bounces at lists.arcs.org.au] On Behalf Of Stephen M
Richard
Sent: Wednesday, 2 September 2009 18:15
To: auscope-geosciml at lists.arcs.org.au
Subject: Re: [Auscope-geosciml] CGI Value abomination [SEC=UNCLASSIFIED]

Simon--Interoperability is defined by some community of practice. Sure, some
group could agree to some free text format for data interchange, but then
they'd dispense with xml and OGC services entirely and pass around
tab-delimited text files.  We've been there, and know how well or poorly
that works.

What is the problem with leaving the xml schema quite general, allowing for
different value quantification schemes, with the understanding that
communities wishing to share data using GeoSciML services will have to
develop an application profile restricting some of the possibilities? 
The benefit of the model is in establishing patterns for how this is done,
so that each solution to the same problem is not different.

To me the important question for Quebec is how much we can do using SWE,
since the value quantification issue is certainly not only a geoscience
problem! Maybe replace CGI_Value with some element (swe:DataArray?) or
elements from SWE. We need to analyze the places CGI_Value is used in
GeoSciML (see list below), and figure out if there is more than one pattern,
and decide if we need to change it.

steve

> CGI_Value is used for:
> Bedding thickness
> Event age
> part proportion (GUPart, composition, rock constituent part) several 
> geophyscial properties (magnetic susceptibility, permeability, 
> porosity, CGI_PhysicalDescription) mapped feature position accuracy 
> trend, plunge, azimuth and dip on orientation values particle geometry 
> description properties (grain size, sorting, shape, and aspect ratio)



Simon Cox wrote:
> In that case you can make everything that is not an 'interoperable' 
> field just free-text.
> This would still say that CGI-Value could be dispensed with.  
>
>
> --------------------------------------------------------
> Simon Cox
>
> European Commission, Joint Research Centre, Institute for Environment 
> and Sustainability, Spatial Data Infrastructures Unit, TP 262 Via E. 
> Fermi, 2749, I-21027 Ispra (VA), Italy
> Tel: +39 0332 78 3652
> Fax: +39 0332 78 6325
> mailto:simon.cox at jrc.ec.europa.eu
> http://ies.jrc.ec.europa.eu/simon-cox
>
> SDI Unit: http://sdi.jrc.ec.europa.eu/ IES Institute: 
> http://ies.jrc.ec.europa.eu/
> JRC: http://www.jrc.ec.europa.eu/
> --------------------------------------------------------
>
> -----Original Message-----
> From: auscope-geosciml-bounces at lists.arcs.org.au
> [mailto:auscope-geosciml-bounces at lists.arcs.org.au] On Behalf Of 
> Laxton, John L
> Sent: Wednesday, 2 September 2009 11:39
> To: auscope-geosciml at lists.arcs.org.au
> Subject: Re: [Auscope-geosciml] CGI Value abomination 
> [SEC=UNCLASSIFIED]
>
> The snag with limiting users to the number of formats they can use is 
> that the chosen format may not match the user's database. We recently 
> hit this with unitThickness defined as CGI_Numeric. Fair enough you 
> might think but in our database unit thickness is a string with 
> comments like 'c23m in Grantham area'. The unfortunate reality is that 
> in lots of cases different data providers hold the same property in 
> different formats. We could remodel them as distinct properties for 
> different formats (Ollie's option (b)) but this is only going to be 
> worthwhile where we wish to query against the property. In most cases 
> all we wish to do is deliver a property value and I'm not convinced it 
> matters if the way BGS delivers something like 
> ParticleGeometryDescription.sorting is different from the way AZGS 
> does - we need to be realistic about the level of interoperability 
> needed. Particular services can always specify more restrictive
requirements if needed as OneGeology-Europe is doing.
>
> John
>
> -----Original Message-----
> From: auscope-geosciml-bounces at lists.arcs.org.au
> [mailto:auscope-geosciml-bounces at lists.arcs.org.au] On Behalf Of 
> Oliver.Raymond at ga.gov.au
> Sent: 02 September 2009 05:49
> To: Rob.Atkinson at csiro.au; auscope-geosciml at lists.arcs.org.au
> Subject: Re: [Auscope-geosciml] CGI Value abomination 
> [SEC=UNCLASSIFIED]
>
> I agree with Simon's sentiments.  But Rob's comments have me confused.  
> I can't see how making CGI_Value a specialisation of another class is 
> going to make the model more interoperable.  It still leaves users 
> able to deliver some attribute values as either term values, number values
or ranges.
>
> The aim here is to:
>
> a) limit users in the number of formats they can use to deliver 
> attribute values, and
>
> b) redefine some model elements (eg: Age) so that they explicitly 
> state, for example, "this attribute is for a numerical Age only" or 
> "this attribute is for a term Age only", rather than the existing 
> "this attribute can be a numeric Age, or a term Age, or a range of numeric
and term Ages".
>
> Cheers,
> Ollie
>
>   
...clipped...

--
Stephen M. Richard
Section Chief, Geoinformatics
Arizona Geological Survey
416 W. Congress St., #100
Tucson, Arizona, 85701 USA

Phone: 
Office: (520) 209-4127
Reception: (520) 770-3500
FAX: (520) 770-3505

email: steve.richard at azgs.az.gov

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