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

Table of Contents: Coverages and Web Coverage Service: the Big Picture OGC coverage data and service standards overview diagram Coverage specifications (with adoption status) Coverage data model: WCS service model: OAPI-Coverages service model: Coverage Analytics: Non-Coverage documents: Technical Coverage resources ISO TC211

OGC coverage data and service standards overview diagram

Figure: Coverage data and service model overview

Coverage specifications (with adoption status)

All coverage-related adopted standards - in particular: the CIS and WCS suites - can be found on the OGC WCS page, except for the WCPS language definition which is maintained separately for historical reasons.

Coverage data model:

• Core:
  • Coverage Implementation Schema (CIS), version 1.1 document and schemas for XML, JSON, RDF and examples: (adopted, backwards compatible next version of CIS/GMLCOV 1.0); key features (see rationales):
    • CIS 1.1 is backwards compatible to CIS/GMLCOV 1.0, and does not require any change to WCS 2.0 (just a formal extension to allow WCS instances serve the new coverage types - 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)
  • Coverage Implementation Schema (CIS), version 1.0.1 document and schema, OGC 09-146r2: adopted
    • renamed GML 3.2.1 Application Schema - Coverages (GMLCOV) to Coverage Implementation Schema (CIS) resulting from a renaming of OGC 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)
• format encoding extensions:
  • GML Application Schema - Coverages - GeoTIFF Coverage Encoding Profile, version 1.0, OGC 12-100r1: adopted
  • GML Application Schema - Coverages - JPEG2000 Coverage Encoding Profile, version 1.0, OGC 12-108: adopted
  • CF-netCDF 3.0 encoding using GML Coverage Application Schema, version 2.0, OGC 14-100r2: adopted
  • GRIB2 Encoding Profile: under adoption vote
  • JPIP Coverage Encoding Profile: activities commenced
• data model extensions:
  • Coverage Implementation Schema - ReferenceableGridCoverage Extension, OGC 16-083r2: adopted extension to CIS 1.0
    • This standard closes a gap of GML 3.2.1 inherited by CIS 1.0 which has left ReferenceableGridCoverage underspecified. While CIS 1.1 GeneralGridCoverage encompasses the concept of ReferenceableGridCoverages some stakeholders requested to specifically provide this coverage type. Therefore, this standard has been crafted as an extension to CIS 1.0.

WCS service model:

• Core:
  • WCS Core, version 2.1.0 document and schema and examples, OGC 17-089: adopted (no change/update of functionality - only needed to allow CIS 1.1 coverages)
  • WCS Core, version 2.0.1 document and schema and examples, OGC 09-110r4: adopted
• service extensions:
  • WCS Interface Standard - Range Subsetting Extension, version 1.0.0, OGC 12-040: adopted
  • WCS Interface Standard - Scaling Extension, version 1.0.0, OGC 12-039: adopted
  • WCS Interface Standard - CRS Extension, version 1.0.0, OGC 11-053: adopted
  • WCS Interface Standard - Interpolation Extension, version 1.0.0, OGC 12-049: adopted
  • WCS Interface Standard - Processing Extension, version 2.0.0, OGC 08-059r4: adopted
  • WCS Interface Standard - Transaction Extension, version 2.0.0, OGC 13-057: adopted
  • WCS Extension - Web Query Service, version 1.0.0, OGC 14-121: on hold as per OAB as it might go into OWS Common
• protocol binding extensions:
  • WCS Interface Standard - KVP Protocol Binding Extension, version 1.0.1, OGC 09-147r3: adopted
  • WCS Interface Standard - POST/XML Protocol Binding Extension, version 1.0.0, OGC 09-148r1: adopted
  • WCS Interface Standard - SOAP Protocol Binding Extension, version 1.0.0, OGC 09-149r1: adopted
  • WCS Interface Standard - REST Protocol Binding Extension, version 1.0.0, OGC 12-174: under discussion
  • OAPI-Coverages: work in progress
• Application Profiles:
  • WCS 2.0 Interface Standard - Earth Observation Application Profile (EO-WCS), version 1.0, OGC 10-140: adopted
  • WCS 2.0 Interface Standard - Earth Observation Application Profile (EO-WCS), version 1.1, OGC 10-140r2: adopted
  • WCS Application Profile - MetOcean ("MetOcean-WCS"), version 1.0.0: adopted
    • WCS MetOcean Application Profile: Part 0 - MetOcean Metadata, OGC 15-045r7
    • WCS MetOcean Application profile: Part 1 - MetOcean GetCorridor Extension, OGC 15-108r3
    • WCS MetOcean Application profile: Part 2 - MetOcean GetPolygon Extension, OGC 17-086r3

OAPI-Coverages service model:

• OAPI-Coverages is an additional OGC service interface, based on the OGC Coverage Implementation Schema (CIS) data model; it aims at an increased harmonization across OGC services, resulting in a complete OAPI family.
• from a WCS perspective, OAPI-Coverages constitutes an additional protocol binding for serving CIS coverages
• at Geospatial World Forum '21 an overview on OAPI-Coverages and its relation to WCS has been presented

Coverage Analytics:

• datacube analytics:
  • Web Coverage Processing Service (WCPS) Language Interface Standard
    • version 1.1.0 OGC 08-068r3: adopted Interface Standard
    • version 1.0.0, OGC 08-068r2: adopted Interface Standard
  • ISO 19123-3 Coverage Processing Fundamentals -- unofficial draft
    • Coverages.SWG presenttion of 19123-3 draft
• data / metadata integration:
  • Web Query Service (WQS) 1.0, OGC 14-121 Best Practice

Non-Coverage documents:

• CRS Name Type Specification, version 1.0.0, OGC 11-135r2: adopted
• WPS Application Profile - Coverages, version 2.0.0, OGC 09-045r1, adopted Discussion Paper

Technical Coverage resources

• OGC WCS schema location -- normative
• ISO EA UML model -- normative
• Coverage data and service UML model -- non-normative
• 15-065r1_Testbed_11_Referenceable_Grid_Harmonization_Engineering_Report_FINAL.pdf: Testbed-11 Engineering Report motivating CIS 1.1

ISO TC211

These are drafts of advanced ISO TC211 specifications under way for adoption. WARNING: these are not adopted standards, and may not get adopted verbatim. They are just provided "as is" for community information.

• ISO DIS 19123-1 under FDIS ballot, replacing ISO IS 19123:2005 and candidate replacement for OGC Abstract Topic 6
• ISO DIS 19123-3, under FDIS ballot