[OSGeodata] geodata schema

[Jo Walsh]

dear Stefan, all; sorry for my response lag on this - i'm still
playing email catchup from my week offline last week. :/

On Tue, Aug 01, 2006 at 08:02:14PM +0200, sfkeller at hsr.ch wrote:
> Didn't realize this. This seems to borrow the information model from
> FGDC. How much was this model discussed? For future compatibility, I
> would either take an 'enhanced' set of attributes from pure core ISO
> 19115/19 
This is an implementation of 
http://wiki.osgeo.org/index.php/Geodata_Metadata_Requirements
which in turn is an attempt to extract the 'simplest useful thing'
from FGDC metadata, and bolt on some Dublin Core properties and also
expressions about OGC web services interfaces. This was put together
over a couple of longish discussions at IRC meetings in April/May. It
doesn't represent a "public recommendation" but a representation of
what OSGeo and telascience members need as a baseline for our own data
repository, which we hope will be useful to others. 

> or an extended and specialized set of Dublin Core elements in
> RDF, which would give geodata an even broader outreach through Google
> with the help of OAI-PMH (c.f. below). Regarding FGDC and ISO 19115: I
> found that the so called core lacks mandatory Dublin Core elements which
> is a pity. 

Why not OAI-PMH, i would say 1/ because none of us really knew it. 
http://www.oaforum.org/tutorial/english/page3.htm outlines a
nice simple worldview - 6 http based requests - 
But we'll *definitely* need to extend beyond this 
- I want to be able to send spatial and temporal bounding boxes to a 
RESTful interfaces and get back data sets constrained by this. 
I guess being able to say 'OAI-PMH compatible' is a win?

I've always thought of this as a data-driven not "metadata-driven"
activity - thus 'ListMetadataFormats' doesn't make that much sense to
me. Model first, format is syntactic sugar almost? ;) 
I guess I'd envisioned results coming out mainly in RSS1.0 (RDF)
with GeoRSS expressions - cf http://georss.org/  - and also optionally
in that lovely tab-delimited FGDC format :) - and FGDC xml if people
really want that too.

I hadn't thought about this in syndication/crawler terms, until i
actually looked at it, and thought, well it would work both ways, and
i'm already using GDAL/OGR and starting to use OWSLib to automate 
spatial indexing of shapefiles, etc, and OGC web services, respectively.

> > My motivation is to avoid the CSW-ebRim profile

Definitely, it sounds painful.
> 
> Regarding the protocol I see three choices: 1. CSW 2, 2. WFS and 3.
> OAI-PMH.

+1 on using the very basic OAI-PMH 6 functions, seeing if they're all
useful to us, and extending them, and then arguing about it via the 
medium of bots. 

cheers,


jo