Coverages and Web Coverage Service: the Big Picture

This page gives an overview of the coverage data model and the WCS service suite. -- PeterBaumann - 07 May 2013

OGC coverage data and service standards overview diagram


Coverage specifications (with adoption status)

Coverage data model:
  • core:
    • Coverage Implementation Schema (CIS), aka GML 3.2.1 Application Schema - Coverages (GMLCOV), version 1.0.1, OGC 09-146r2: adopted
    • Coverage Implementation Schema (CIS), version 1.1 (candidate standard, backwards compatible next version of CIS/GMLCOV 1.0); key features:
      • renamed GMLCOV to CIS to better reflect contents of the standard (too many people believed GMLCOV is just a GML encoding, while it actually defines interoperable coverage structures in a format-independent way)
      • CIS 1.1 is backwards compatible to GMLCOV 1.0, and does not require any change to WCS 2.0 (just an extension to allow WCS instances serve the new coverage types - this will be accomplished by WCS 2.1)
      • instead of the cumbersome grid distinction of Rectified / Referenceable Grid, various axis types are defined: non-referenced, regular, irregular, etc; these axis types can be combined arbitrarily in a coverage (eg, regular, rectified Lat and Long axes together with an irregular time axis)
      • support for grids as per SensorML 2.0
      • coverages can be partitioned into sub-coverages while still acting as one (eg, in a WCS GetCoverage request)
      • prepared for JSON support (next version)
  • format encoding extensions:
  • ReferenceableGridCoverage Extension-- a proposed extension for GMLCOV 1.0 --
    • is meant as an interim standard [OGC 16-083] until the candidate coverage standard CIS 1.1 becomes official and relevant encoding standards dependent on GMLCOV 1.0 are updated.
      • In particular, GMLJP2 will be updated for CIS 1.1 after ISO 19123 is revised so that they are in-sync.
        • This ISO 19123 revision work will (reportedly) begin in 2017 or 2018.
    • is a strict (and minimal) extension of the current coverage standard, with 4 referenceable grid elements all under a single namespace:
      • ReferenceableGridBySensorModel
        • based on SensorML 2.0 documents
      • The 3 referenceable grid elements adapted from GML 3.3:
        • ReferenceableGridByVectors, ReferenceableGridByArray, and ReferenceableGridByTransformation
        • are adapted in order to avoid a known harmonization conflict between GMLCOV 1.0 and GML 3.3:
          • While the GML 3.3 elements are based on AbstractReferenceableGrid from GML 3.3, ReferenceableGridCoverage must use elements based on AbstractReferenceableGrid from GMLCOV (not from GML 3.3)
            • This is Requirement 14 of GMLCOV 1.0 [OGC 09-146r2]

WCS service model:


Technical resources

  • Coverage Implementation Schema 1.1 (draft candidate standard)
Topic attachments
I Attachment Action Size Date Who Comment
09-045r1_WPS_Application-Profile_-_Coverages_2014-11-04.zipzip manage 62.3 K 02 Jan 2015 - 14:24 PeterBaumann 09-045r1 WPS Application Profile - Coverages
09-146r3_Coverage-Implementation-Schema_2016-04-14.zipzip manage 731.1 K 14 Apr 2016 - 16:04 PeterBaumann Coverage Implementation Schema 1.1 (draft, incorporating RFC comments)
13-057_WCS_Extension_-_Transaction_2014-09-15.zipzip manage 146.4 K 09 Dec 2015 - 14:50 PeterBaumann 13-057 WCS Extension - Transaction
14-121_WCS_Extension_-_XPath_2014-12-01.docxdocx 14-121_WCS_Extension_-_XPath_2014-12-01.docx manage 96.5 K 17 Dec 2015 - 15:33 PeterBaumann 14-121 WCS Extension - XPath (draft)
14-121_Web-Information-Service_2016-05-18.zipzip manage 94.7 K 03 Jun 2016 - 21:14 PeterBaumann OGC Web Information Service (WIS) 1.0
16-083_ReferenceableGridCoverage_Extension.zipzip manage 101.3 K 24 Jun 2016 - 20:58 EricHirschorn GMLCOV 1.0 ReferenceableGridCoverage Extension, updated on June 24, 2016
cis_1-1.zipzip manage 867.9 K 04 Apr 2017 - 10:18 PeterBaumann Coverage Implementation Schema 1.1 (adopted standard)
wcs-spec-hierarchy.pngpng wcs-spec-hierarchy.png manage 82.4 K 13 Mar 2014 - 11:40 PeterBaumann OGC coverage data and service standards overview diagram
wcs_2016-01-16.eapeap wcs_2016-01-16.eap manage 3572.0 K 17 Jan 2017 - 15:18 PeterBaumann coverage data and service UML model (non-authoritative, not necessarily up-to date)
Topic revision: r33 - 27 Apr 2017, PeterBaumann

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