This document defines an extension to WCS2.1, namely the extraction of data along a corridor defined by a path and corridor extent consisting of an information model and an XML encoding for the following two operations:
GetCapabilities — a WCS function that describes the services and operations via a GetCapabilities document.
GetCorridor — a WCS function that supports this operation to extract data from a multidimensional cube along a path, or corridor.
Metadata and vocabularies are defined that provide interoperability of these operations and documents using common semantics. The information model proposed supports MetOcean specific concepts and its user community, but these constructs may be useful and applicable to other communities.
The following are keywords to be used by search engines and document catalogues.
ogcdoc, OGC document, WCS, coverage, collection, meteorology, oceanography, NWP, analysis, result mask, observation, measurement, simulation, O&M, trajectory, corridor and MetOcean
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The Open Geospatial Consortium shall not be held responsible for identifying any or all such patent rights.
Recipients of this document are requested to submit, with their comments, notification of any relevant patent claims or other intellectual property rights of which they may be aware that might be infringed by any implementation of the standard set forth in this document, and to provide supporting documentation.
IV. Security Considerations
No security considerations have been made for this standard.
V. Submitting Organizations
The following organizations submitted this Document to the Open Geospatial Consortium (OGC):
- Met Office, UK
- NOAA’s National Weather Service
All questions regarding this submission should be directed to the editor or the submitters:
|Peter Trevelyan||Met Office, UK|
National Oceanic and Atmospheric Administration (NOAA)
National Weather Service (NWS)
National Oceanic and Atmospheric Administration (NOAA)
National Weather Service (NWS)
OGC MetOcean Application profile for WCS2.1: Part 1 MetOcean GetCorridor Extension
The purpose of the GetCorridor operation is to extract a corridor based on a trajectory from a multidimensional coverage. The need for the getCorridor operation stems from active members of the OGC MetOcean Domain Working Group (DWG) who saw a manifest need for extraction of such information from gridded datasets. This work has been done by members of the OGC MetOcean Domain Working Group.
This standard defines:
An amended GetCapabilities operation response that will list the GetTrajectory operation and specify the token in the Sections element of the GetCapabilities request.
A new operation “GetCorridor” that is used to extract data from a multidimensional cube along a path or trajectory.
The conformance classes that describe the GetCorridor operation.
Conformance with this standard shall be checked using all the relevant tests specified in Annex A (normative) of this document. The framework, concepts, and methodology for testing, and the criteria to be achieved to claim conformance are specified in the OGC Compliance Testing Policies and Procedures and the OGC Compliance Testing web site1.
In order to conform to this OGC™ interface standard, a software implementation shall choose to implement: http://cite.opengeospatial.org/
Any one of the conformance levels specified in Annex A (normative).
All requirements-classes and conformance-classes described in this document are owned by the standard(s) identified.
Requirements and conformance test URIs defined in this document are relative to: http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/
This document establishes the following requirements and conformance classes:
GetCorridor of URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/req/getCorridor defining getCorridor at a conceptual level in clause 8.1.
The corresponding conformance class is getCorridor with URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/conf/getCorridor See A.1
PathDescription of http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/req/PathDescription defining the PathDescription at a conceptual level in clause 8.2
The corresponding conformance class is PathDescription with URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/conf/PathDescription . See A.2
CorridorExtent of URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/req/CorridorExtent defining the CorridorExtent at a conceptual level in clause 8.3;
The corresponding conformance class is CorridorExtent with URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/conf/CorridorExtent . See A.3
CorridorExtractionMethod of URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/req/CorridorExtractionMethod defining the CorridorExtractionMethod at a conceptual level in clause 8.4;
The corresponding conformance class is CorridorExtractionMethod with URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/conf/CorridorExtractionMethod . See A.4
GetCorridor-post-xml of URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/req/getCorridor-post-xml defining GetCorridor-post-xml on the conceptual level in clause 8.5
The corresponding conformance class is offering with URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/conf/getCorridor-post-xml . See A.5
GetCorridor-simple of URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/req/getCorridor-simple defining GetCorridor-simple on the conceptual level in clause 8.6
The corresponding conformance class is offering with URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/conf/getCorridor-simple See A.6
GetCorridor-simple-kvp of URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/req/getCorridor-simple-get-kvp defining GetCorridor-simple on the conceptual level in clause 8.7
The corresponding conformance class is offering with URI http://www.opengis.net/spec/WCS_application-profile_metocean_corridor/1.0/conf/getCorridor-simple-get-kvp See A.7
3. Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
Policy SWG: OGC 08-131r3, The Specification Model — Standard for Modular specifications. Open Geospatial Consortium (2009). https://portal.ogc.org/files/?artifact_id=34762&version=2
ISO: ISO/TS 19103:2005, Geographic information — Conceptual schema language. International Organization for Standardization, Geneva (2005). https://www.iso.org/standard/37800.html
ISO: ISO 8601:2004, Data elements and interchange formats — Information interchange — Representation of dates and times. International Organization for Standardization, Geneva (2004). https://www.iso.org/standard/40874.html
ISO: ISO 19107:2019, Geographic information — Spatial schema. International Organization for Standardization, Geneva (2019). https://www.iso.org/standard/66175.html
ISO: ISO 19111:2007, Geographic information — Spatial referencing by coordinates. International Organization for Standardization, Geneva (2007). https://www.iso.org/standard/41126.html
ISO: ISO 19123:2005, Geographic information — Schema for coverage geometry and functions. International Organization for Standardization, Geneva (2005). https://www.iso.org/standard/40121.html
ISO: ISO 19115-1:2014, Geographic information — Metadata — Part 1: Fundamentals. International Organization for Standardization, Geneva (2014). https://www.iso.org/standard/53798.html
ISO: ISO 19156:2011, Geographic information — Observations and measurements. International Organization for Standardization, Geneva (2011). https://www.iso.org/standard/32574.html
ISO: ISO 19136:2007, Geographic information — Geography Markup Language (GML). International Organization for Standardization, Geneva (2007). https://www.iso.org/standard/32554.html
Peter Baumann: OGC 17-089r1, OGC Web Coverage Service (WCS) 2.1 Interface Standard — Core. Open Geospatial Consortium (2018). http://docs.opengeospatial.org/is/17-089r1/17-089r1.html
Marie-Françoise Voidrot-Martinez, Chris Little, Jürgen Seib, Roy Ladner, Adrian Custer, Jeff de La B: OGC 12-111r1, OGC Best Practice for using Web Map Services (WMS) with Time-Dependent or Elevation-Dependent Data. Open Geospatial Consortium (2014). https://portal.ogc.org/files/?artifact_id=56394
Simon Cox: OGC 10-025r1, Observations and Measurements — XML Implementation. Open Geospatial Consortium (2011). https://portal.ogc.org/files/?artifact_id=41510
Alexandre Robin: OGC 08-094r1, OGC® SWE Common Data Model Encoding Standard. Open Geospatial Consortium (2011). https://portal.ogc.org/files/?artifact_id=41157
Peter Baumann, Eric Hirschorn, Joan Masó: OGC 09-146r8, OGC Coverage Implementation Schema with Corrigendum. Open Geospatial Consortium (2019). http://docs.opengeospatial.org/is/09-146r8/09-146r8.html
Arliss Whiteside Jim Greenwood : OGC 06-121r9, OGC Web Service Common Implementation Specification. Open Geospatial Consortium (2010). https://portal.ogc.org/files/?artifact_id=38867
UCUM: Unified Code for Units of Measure (UCUM) – Version 1.9, 2013, http://unitsofmeasure.org/
OMG UML 2.5.1, Unified Modeling Language. (2017). https://www.omg.org/spec/UML/2.5.1/
W3C: Extensible Mark-up Language (XML) – Version 1.0 (Fifth Edition), August 2008
W3C: XML Schema – Version 1.0 (Second Edition), October 2004
Peter Baumann, Jinsongdi Yu: OGC 12-039, OGC® Web Coverage Service Interface Standard — Scaling Extension. Open Geospatial Consortium (2014). https://portal.ogc.org/files/?artifact_id=54504
Peter Baumann, Jinsongdi Yu: OGC 12-049, OGC® Web Coverage Service Interface Standard — Interpolation Extension. Open Geospatial Consortium (2014). https://portal.ogc.org/files/?artifact_id=54502
Peter Baumann, Jinsongdi Yu: OGC 11-053r1, OGC® Web Coverage Service Interface Standard — CRS Extension. Open Geospatial Consortium (2014). https://portal.ogc.org/files/?artifact_id=54209
Peter Trevelyan, Paul Hershberg, Steve Olson: OGC 15-045r7, OGC MetOcean Application profile for WCS2.1: Part 0 MetOcean Metadata. Open Geospatial Consortium (2020)
4. Terms and definitions
For the purposes of this document, the following terms and definitions apply.
This document uses the terms defined in Sub-clause 5.3 of OGC 06-121r9, which is based on the ISO/IEC Directives, Part 2, Rules for the structure and drafting of International Standards. In particular, the word “shall” (not “must”) is the verb form used to indicate a requirement to be strictly followed to conform to this standard.
This document also uses terms defined in the OGC Standard for Modular specifications (OGC 08-131r3), also known as the ‘ModSpec’. The definitions of terms such as standard, specification, requirement, and conformance test are provided in the ModSpec.
For the purposes of this document, the following additional terms and definitions apply.
numerical weather prediction model
A Numerical Weather Prediction (NWP) model is a mathematical model of the atmosphere and oceans used to predict the weather based on current weather conditions and are normally run at set times each day.
Synonyms for numerical weather prediction model: forecast model, NWP Model, simulation
An Example of a numerical weather prediction model: The ECMWF model that runs twice per day and creates a ten day prediction of the global atmosphere.
Reference time is a temporal parameter used to represent a time axis that can be mapped to some relevant referent time other than validity time. The semantic meaning can differ for different types of data. For numerical weather forecasts, it may be a nominal time where observations have been assimilated to initialize the calculation. Synonym for reference time: model run time.
An example of reference time: 2017-12-12T00.00.00Z
Note 1 to entry: “reference time” will used in preference to “model run time” as it is more generic and includes services that may be continually updated.
Validity time is an attribute value specified by an instant in, or duration of, universal chronological time that identifies when information is valid or applicable. In ISO 19156, the validity time has the semantics of phenomenonTime. Deciding if the data have a ‘validity time’ is an important step.
Synonyms for validity time: verification time.
An example of validity time 2017-12-12T12.00.00Z
Note 1 to entry: Forecast models running with different reference times will have, for some fields, the same verification time if the durations of the different model runs overlap.
GRIB stands for Gridded Binary. GRIB is a WMO (World Meteorological Organisation) format for gridded binary data exchanged between member countries, including a controlled vocabulary defined in tables.
Web Coverage Service 2.1 (WCS2.1)
Web Coverage Service (WCS) is an OGC standard that refers to the exchange of geospatial information as ‘coverages’: digital geospatial information representing space-varying phenomena.
The getCapabilities is a WCS operation involving a machine to machine communication. A getCapabilities request to a WCS server returns a a list of what operations and services (“capabilities”) are being offered by that server.
A DescribeCoverage is a WCS operation involving a machine to machine communication. A DescribeCoverage request to a WCS server returns additional information about a coverage that a client wants to query. Generally speaking, a DescribeCoverage response includes information about the CRS, the metadata, the domain, the range and the formats available. A client generally will need to issue a DescribeCoverage request before it can make the proper GetCoverage request.
The path is simply the route or course along which something travels or moves, for example the path of an aeroplane.
A Corridor, in this document, is a trajectory (aka path) with a lateral and vertical extent. The corridor may be multi-dimensional, and in the case of aviation is often four dimension, i.e. x, y, z, t.
The GetCorridor is a newly proposed MetOcean operation involving a machine to machine communication. A GetCorridor request to a WCS server returns a corridor coverage based on a trajectory path with a lateral and vertical extent (the corridor).
This sections provides details and examples for any conventions used in the document. Examples of conventions are symbols, abbreviations, use of XML schema, or special notes regarding how to read the document.
5.1. Abbreviated terms
GML Geography Markup Language
O&M Observations and Measurements
OGC Open Geospatial Consortium
NWP Numerical Weather Prediction
SWE OGC Sensor Web Enablement
UML Unified Modelling Language
WCS2.0 OGC Web Coverage Service version 2.0
WCS2.1 OGC Web Coverage Service version 2.1
WMO World Meteorological Organization
XML W3C Extensible Markup Language
XSD W3C XML Schema Definition Language
5.2. Schema language
The XML implementation specified in this Standard is described using the XML Schema language (XSD) [XML Schema Part 1: Structures, XML Schema Part 2: Datatypes] and Schematron [ISO/IEC 19757-3, Information technology — Document Schema Definition Languages (DSDL) — Part 3: Rule-based validation — Schematron].
5.3. UML notation
The diagrams that appear in this standard are presented using the Unified Modeling Language (UML) static structure diagram.
Note: Within the context of this standard, the following color scheme is used to identify the package in which the class exists. This is just for informative purposes.
Blue: WCS2.1 plus extensions (rsub, scal, int and crs)
Orange: CIS (Coverage Implantation Schema 1.1)
Green: This standard
This standard defines a number of properties that require the use of codes or vocabulary items. In some cases a list of terms is provided. The MetOcean Profile, on which this builds, has a specific vocabulary provided by the WMO (World Meteorological Office). These vocabularies are concerned with the naming of parameters (variables) used in the rsub:RangeSubset element, the coordinate reference systems (aka fixedSurfacetypeAndUnits) used in the srsName attribute, the units of measure, and the significance of time codes. The following table lists the references used within this document.
Table 1 — Summary of vocabularies within this standard
|Code list||Code reference|
|GRIB edition 2||http://codes.wmo.int/_grib2|
|Fixed surface types and units||http://codes.wmo.int/grib2/codeflag/_4.5|
7. Non-Normative (Informative) Material
The GetCorridor extension for WCS2.1 is an initiative of the MetOcean DWG to enhance the WCS2.1 core profile to extract coverages other than those extracted using the simple SLICE and TRIM methods provided by the core GetCoverage operation see Figure 1. See the OGC® Web Coverage Service 2.1 Interface Standard — Core (OGC 17-089r1). This specific extension is designed specifically to extract corridors from multidimensional cubes such as those created by numerical simulations (i.e. NWP) commonly found in the MetOcean community.