Copyright © 2012 Open Geospatial Consortium
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6.3 Coordinate Reference System CRS
The following sections have been extracted from:
https:portal.opengeospatial.orgtwikibinviewOWS8AviationWeatherCrs OGC Web Coverage Service specification v 2.0
http:www.opengeospatial.orgstandardswcs WCS Core change request CR
https:portal.opengeospatial.orgfiles?artifact_id=44308
Weather Exchange Information Model WXXM http:www.eurocontrol.intaimpublicstandard_pagemet_wie.html
Encoding Representative Weather Datasets https:portal.opengeospatial.orgfiles?artifact_id=46115
6.3.1 Overview
The Coordinate Reference System CRS Domain Working Group develops strategies for encoding the earth coordinate reference systems and transformations between coordinate
reference systems. The group has worked consistently on the joint OGC-ISO Document 19111 - Spatial Referencing by Coordinates.
The Aviation Thread of OWS-8 will explore ways to address the following two issues: -
How can a WCS client request a specific Coordinate Reference System CRS
including projection, projection parameters, datum, etc when there is no existing EPSG or other code associated with the CRS? How can such CRSs be encoded in this case
well-known text, GML, etc?
- Can a WCS 2.0 server formally advertise the capability to support arbitrary CRSs
as opposed to a fixed number of possible CRSs, as specified in the client query? As a background, in the weather domain, the set of projected spaces of interest to clients
is potentially infinite. For example, a data set available in a Lambert Conformal projection with a certain projection origin and other parameterizations may be requested
by a client in Lambert Azimuthal Equal Area projection with a completely different origin and other parameterization. EPSG codes have been insufficient to describe the
combinations of projections and projection parameters that the clients may require.
From the WCS server perspective, the requirement becomes that of supporting an infinite number of actual CRSs on-demand, and to be able to advertise such capability in their
capabilities statement. Note the focus here is on solutions based on the WCS standard and not on the Web Processing Service WPS, which could also be used to support custom
CRS conversions.