[OSGeo-Standards] Was: "file" formats. Is: GeoWeb

[Rushforth, Peter]

Arnulf,
>Plus - mailing lists are probably no good for long time evolution of
>ideas. Put the other way round: Where do we aggregate those ideas we
>agree about?

+1 for the agreement parts, although arguments work out better in email if
you can just deal with them to the point that we can agree on something.

>> Web mapping: easiest case. Map tiles are good resources

> Not sure whether I agree here. The map tiles are one representation of
>the resource. The resource is the source of the data, for example a set
>aerials taken at the same time and area, or for a defined region. The
>resource also has other representations, for example a meta data record
>of the whole thing or of each tile. The documentation of the grid
>structure of the tiles is yet another representation of the same resource.

>> Vector data: harder. Features are good resources, and a feature
>> collection (what we often call a layer) is a good aggregate resource,

>Again, not sure whether I can agree. The resource is the collection of
>all the features. 

Although it sounds stupid to say "the earth" is the resource, we're talking
about the GeoWeb anyway so it's not so stupid, I think.  When
you think about the resource - representation duality, any subset can
equally be considered a representation of it, be that a tile, a group of tiles,
a tilematrixset, or a FeatureCollection representation of any of those things.  
So the representation notion doesn't simply cover the
format aspect, it also allows us to push the understanding of "the earth"
how to interact with the resource into the format, hence the value of "east"
"west" etc., which become part of a "what you can expect in this format" 
specification i.e. a media type registration.


>Then each feature can be queried in different
>representations (formats). Just a simple example (not saying that this
>is perfect, just for demonstration purposes):
>http://data.ordnancesurvey.co.uk/doc/geometry/37256-10


That's all I've got time for now.  More later, but discussion welcome.

Cheers,
Peter