[OSGeodata] Geodata Metadata Requirements

[Ned Horning]

Jo,

Thanks for taking the time to get this going. It's good to have a structure
to build around. I have a number of questions and comments. This is not my
area of expertise so I apologize in advance if I'm off base on some of this.


Although there are advantages to adding more structure I wouldn't drop all
of the full-text fields. I'm concerned that we would loose essential
description information without some full-text. For example, "description"
information is probably best left as full-text. It's fine to add structured
fields for important "description" components but I'd hesitate dropping the
full-text field. I may be in the minority but I actually read some of these
text fields. 

Why are there different "datasource" fields for TorrentFile, WMS,
shapefile.? It seems like a mix of data models, data compression, data
delivery, file formats. Why not just one "datasource" field. Maybe I don't
understand what a "datasource" is. I expect the answer is obvious but I just
don't see it.

What's the difference between "projection" and 'spatial reference"? Isn't a
projection part of a spatial reference?

Why do we need a different spatial reference for raster and vector models.
What about other data models?

It would probably be good to have information about ownership and how/where
it can be accessed. 

If quality assurance is the driving force behind creating the metadata it
would be useful to add some fields related to quality.  

I hope this is useful.

All the best, 

Ned 
> -----Original Message-----
> From: Jo Walsh [mailto:jo at frot.org]
> Sent: Monday, April 10, 2006 6:39 PM
> To: geodata at geodata.osgeo.org
> Subject: [OSGeodata] Geodata Metadata Requirements
> 
> dear all,
> 
> http://wiki.osgeo.org/index.php/Geodata_Metadata_Requirements
> 
> = Why this document exists =
> 
> One goal of the [[Public Geospatial Data Project]] is to offer, in the
> future, a repository of reusable public geographic data that can
> support open source geospatial software projects, both inside and
> outside the foundation.
> 
> One big requirement for a potential [[Geodata Repository]] is that
> there be a well-defined baseline for metadata. This can be seen as a
> quality assurance effort - data won't be accepted without a certain
> amount of metadata.
> 
> The [http://www.fgdc.gov/metadata/|US Federal Geographic Data
> Committee metadata standard] emphasises conformance, but doesn't
> emphasise exchangeability / reusability. FDGC is standard for "Spatial
> Data Infrastucture" efforts, but doesn't have much of a "geospatial
> web" orientation.
> 
> There are some properties in addition to FGDC which it would be really
> useful to have - different distribution channels like WFS, bittorrent
> which have come into existence since FGDC was originally defined. For
> many elements, FGDC asks for full-text descriptions. More structure in
> descriptions would help with automating discovery or re-use.
> 
> This is a "straw-person" set of suggestions, and comment / additional
> references would be gratefully received.
> 
> -----
> 
> While thinking about this, I made an RDF/OWL model using a commandline
> tool, which maps to some but not all of the mandatory fields in FGDC
> and adds some properties that concern data distribution methods that
> have come along since FGDC was designed.
> http://frot.org/osgeo/geometadata.rdf
> http://frot.org/osgeo/geometadata.png - a 'domain model' type graph
> generated from that RDF model. This is partly a thought experiment,
> partly a possible basis for a future prototype, if this gets traction.
> 
> Any additions to that document would be appreciated. I'd quite like to
> try this out on the OpenSDI list and see what they might contrib in
> terms of common knowledge on best practise and future direction about
> this.
> 
> best wishes,
> 
> 
> jo