[georss] [Opensearch-discuss] Spatio-temporal query extension

[Stefan F. Keller]

Sorry, got trapped by reply-to user instead reply-to georss... 2007/3/15,
Pat Cappelaere <pat at cappelaere.com>:

> Stephan,
>
> I do not follow your train of thoughts at all.
>

Sorry, my fault. That's why I asked about the use case before.



> The intent here is to provide an improved and more widely accepted
> interface to WFS-Simple using OpenSearch (which is already integrated in the
> browser and can be discovered).  We all agreed that WFS-Simple does not have
> much in terms of filtering capabilities (spatio-temporal-keyword search).
>

WFS Simple has bbox, time capabilities and we actually proposed regular
expressions for content filtering. Raj let regex stay there explicitely for
discussion. It even has a defined exception handling.

The main thing WFS Simple 'lacks' compared to OpenSearch is an explicit
relation to autodiscovery. This could be where OpenSearch, Google Sitemaps
or KML come in (Google was'nt part of the OpenSearch spec. team but now it
seems that Google GData API supports OpenSearch responses).



> WFS-Simple targets the mass-market GIS users and outputs  Atom/GeoRSS
> format (among others).
>
>
 Using an OpenSearch interface would allow distributed queries across GIS
> and non GIS repositories.
> The RESTful interface is great.
> Passing a bbox attribute is becoming widely accepted. The expected
> response is Atom (or Atom/GeoRSS for GIS Servers) and not XML in our case.
>
> http://www.loc.gov/standards/sru/  does not seem to have spatio-temporal
> query capability that I could find.  CQL seems interesting though but might
> be complex for developers to implement.  Query languages become problematic
> very quickly.
>
> Pat.
>

With ISO 23950/SRU you can make spatio-temporal distributed online queries.
See e.g. http://www.search.gov/geospatial/ which seems to be also a attempt
comining GIS and non GIS repositories. But I agree that implementing a
query interpreter can add complexity. Thats why we suggested regex in WFS
Simple.

Now without knowing your use case better I can't judge which path to follow.
Just my few cents. -- Stefan
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