Re: OGC Ottawa TC meeting highlights

• To: "Ron Lake" <rlake@xxxxxxxxxxxxx>
• Subject: Re: OGC Ottawa TC meeting highlights
• From: "Stefan Falke" <stefan@xxxxxxxxx>
• Date: Thu, 10 May 2007 14:16:37 -0500

Thanks Ron. That chain makes sense. What about chains involving
interactions among WFS, WCS and SOS? For example, one of the examples
that has been discussed (with some liberties taken in my
interpretation) was:

1. Discover a WFS for a surface meteorological network
2. Request DescribeFeature for a temperature sensor to get its sensor
id, sensor type, location, and other descriptive information
3. Request the sensor temperature measurements through a WFS
GetFeature request or a WCS GetCoverage request

Another view in accessing the temperature data might be:

1. Discover a WCS serving surface temperature measurements from a
meteorological network
2. Obtain measurements through a WCS GetCoverage request. The result
would include measurement values and sensor id information.
3. Obtain information about a sensor (or sensors) through a WFS
GetFeature request or a SOS DescribeSensor request

I realize these examples aren't fully resolved (and assume WCS support
for point coverages) but I hope convey the gist of the spec
relationships.

-Stefan

On 5/10/07, Ron Lake <rlake@xxxxxxxxxxxxx> wrote:

Hi Stefan:

One obvious case of service chaining that makes semantic sense to me at
least is that of an FPS (Feature Portrayal Service), a WFS (as currently
understood) and a WRS.  The interaction is something as follows:

1.    The client goes to the WRS and discovers a number of WFS as data
sources.

2.    The client also discovers an FPS.  Note that an FPS exposes a WMS
interface.

3.    The client gets the schemas of the relevent WFS (the ones he/she
wants) from the WFS or the WRS.

4.    The client constructs an SLD and sends a request to the FPS (this is a
WMS request).  The SLD is "filed" with the WRS.

5.    The FPS uses the request to generate requests to each of the WFS
referenced in the SLD.

6.    The GML data returned to the FPS by the various WFS is styled to some
presentation format (e.g. KML, SVG, JPEG) which is returned to the client to
be rendered.

The semantic distinctions are clear here. The FPS/WMS generates and provides
presentations. The WFS participating provide data that is styled for
presentaton by the FPS/WMS. The WRS supports the discovery of all of these
services.

Cheers
 Ron

• References:
  • Re: OGC Ottawa TC meeting highlights
    • From: Stefan Falke
  • RE: OGC Ottawa TC meeting highlights
    • From: Ron Lake