Proposal title

Date	2011/05/19
Contact(s)	Craig Jones
Last edited
Status	draft
Assigned to release	Release number, to be determined
Resources	Patch available
Ticket #	#520

Overview

This proposal is to add an OGC Sensor Observation Service option to the existing OGC WxS Harvester.

This proposal also adds the ability to specify schema specific harvesting for each OGC Service type to the OGC WxS harvester.

Proposal Type

• Type: Module Change
• App: GeoNetwork
• Module: Harvester

Links

• Documents:
• Email discussions:
• Other wiki discussions:

Voting History

• Vote proposed by Craig Jones on 1st June 2011, result was
  • +1 from Patrizia, Emanuele, Jeroen, Francois, Simon

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Motivations

The marine community in Australia is increasingly looking to make use of OGC Sensor Observation services to publish marine data with many services already being made available. The addition of an SOS harvesting option to geonetwork will facilitate the discovery and access of these services via the Australian Oceans Data Network (AODN) by making it a simple process to publish service details to the AODN's service/dataset catalog (the ANZ-MEST/geonetwork) or to contributing catalogs.

Proposal

This proposal adds to the existing OGC WxS harvester. For more details on what this harvester currently does and how it works refer to the existing documentation on this harvester or the original proposal to add this harvester to geonetwork ISO19119impl.

Schema Specific Harvesting

This proposal adds the ability to define schema specific harvesting of OGC WxS GetCapabilities metadata. In particular, the stylesheets to be used to harvest metadata for a particular OGC service type for a particular target output schema are placed in the convert/OGCWxSGetCapabilitiesto19119 directory for the schema or schema plugin. e.g.

For a schema plugin:

  schemaPlugins/iso19139.mcp-1.4/convert/OGCWxSGetCapabilitiesto19119/
    OGCSOSGetCapabilitiesLayer-to-19139.xsl
    OGCSOSGetCapabilities-to-ISO19119_ISO19139.xsl

For one of the core geonetwork schemas:

  xml/schemas/convert/OGCWxSGetCapabilitiesto19119/
    OGCCSWGetCapabilities-to-ISO19119_ISO19139.xsl
    OGCSOSGetCapabilitiesLayer-to-19139.xsl
    OGCSOSGetCapabilities-to-ISO19119_ISO19139.xsl
    OGCWCSGetCapabilitiesLayer-to-19139.xsl
    OGCWCSGetCapabilities-to-ISO19119_ISO19139.xsl
    OGCWFSGetCapabilitiesLayer-to-19139.xsl
    OGCWFSGetCapabilities-to-ISO19119_ISO19139.xsl
    OGCWMSGetCapabilitiesLayer-to-19139.xsl
    OGCWMSGetCapabilities-to-ISO19119_ISO19139.xsl
    OGCWPSGetCapabilities-to-ISO19119_ISO19139.xsl

When a particular OGC Service type is selected in the OGC WxS harvester, all registered schema directories will be scanned to determine which schemas support harvesting metadata for that particular type and the user will be able to select the target schema to use in the harvester:

Schema specific harvesting is also used in the THREDDS and WFS GetFeature harvesters.

SOS GetCapabilities Harvester

This proposal also adds the option to harvest metadata from an OGC Sensor Observation Service GetCapabilities response to the OGC WxS Harvester, in particular an OGC Sensor Observation Service compliant with version 1.0.0 of the specification.

Under this proposal "OGC Sensor Observation service (1.0.0)" will be added to list of possible OGC WxS service types that can be harvested using this harvester:

When this option is selected, the harvester will harvest service metadata from the GetCapabilities statement returned from the specified SOS endpoint using the service metadata stylesheet for the selected target schema.

Additionally, if the "Create metadata for layer elements using GetCapabilities information" option is selected, the harvester will harvest observation offering metadata for each Observation Offering listed in the GetCapabilities response using the observation offering metadata stylesheet for the selected target schema.

An iso19119/iso19139 service metadata stylsesheet and a sample iso19115/iso19139 observation offering metadata stylesheet is included with this proposal (we will be using the iso19139.mcp mapping to be made available in the schema plugin for this profile).

The mappings for the included transformations are as follows:

Service Metadata

Element	ISO19119 equivalent	GetCapabilities element	Note
Service metadata
Identifier	gmd:fileIdentifier/gco:CharacterString	ows:Operation[@name='GetCapabilities']/ows:DCP/ows:HTTP/ows:Get/@xlink:href + @version	Uuid generated from Service url + version
Language	gmd:language/gco:characterString	« eng »	User Input. Default value « eng »
CharacterSet	gmd:CharacterSet/gmd:MD_CharacterSetCode	« utf8 »
HierarchyLevelCode	gmd:hierarchyLevel/gmd:MD_ScopeCode	codeListValue="service"
Contact	gmd:contact	cf contact mapping (refer ISO19119impl)
Date stamp	gmd:dateStamp/gco:DateTime		Harvesting/Import date
Standard name	gmd:metadataStandardName/gco:CharacterString	« ISO 19119/2005 »
Standard version	gmd:metadataStandardVertsion/gco:CharacterString	« 1.0 »
CRS	gmd:referenceSystemInfo/gmd:MD_ReferenceSystem/referenceSystemIdentifier/RS_Identifier/code	sos:ObservationOffering/gml:srsName	4326 if available if not the first one
transferOptions	gmd:distributionInfo/gmd:MD_Distribution/gmd:transferOptions/gmd:MD_DigitalTransferOptions/gmd:onLine	ows:OperationsMetadata/ows:Operation[@name='GetCapabilities']/ows:DCP/ows:HTTP/ows:Get/@xlink:href
dataQualityInfo	leave blank	none
Service Identfication
Title	gmd:citation/gmd:CI_Citation/gmd:title/gco:CharacterString	ows:ServiceIdentification/ows:Title
Date	gmd:citation/gmd:CI_Citation/gmd:date/gmd:CI_Date/gmd:date/gco:dateTime codeListValue=”revision”		Harvesting/Import date
Abstract	gmd:abstract/gco:CharacterString	ows:ServiceIdentification/ows:Abstract
Status	gmd:status/gmd:MD_ProgressCode	« onGoing » or « completed »	if any gml:endPosition/@indeterminatePosition='now' assign <<onGoing>>, otherwise, use <<completed>>
Contact	gmd:pointOfContact	cf contact mapping (refer ISO19119impl)
Keyword	gmd:descriptiveKeywords/gmd:MD_Keywords/gmd:keyword/gco:CharacterString	ows:keywords/ows:Keyword	« theme » for type
Service type	srv:serviceType/gco:LocalName codeSpace="www.w3c.org"	« OGC:SOS »
Service version	srv:serviceTypeVersion/gco:CharacterString	/ROOT/@version	eg. « 1.0.0 »
Fees	srv:accessProperties/gmd:MD_StandardOrderProcess/gmd:fees/gco:CharacterString	ows:Fees
AccessConstraint	gmd:resourceConstraints/gmd:MD_Constraints/gmd:useLimitation	ows:AccessConstraints
Operations	srv:containsOperations/srv:SV_OperationMetadata/srv:operationName/gco:CharacterString	ows:OperationsMetadata/*	cf mapping on operation (refer ISO19119impl)
OperatesOn	srv:operatesOn/gmd:MD_DataIdentification/@uuidref	metadata uuid for generated MD for ObservationOffering
Bounding box	srv:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicBoundingBox	sos:ObservationOffering/gml:boundedBy/gml:Envelope	max upper(nw) and lower (se) of lat/lon values on ObOffering envelopes re-projected to WGS84
Temporal extent	srv:extent/gmd:EX_Extent/gmd:temporalElement/gmd:EX_TemporalExtent	sos:ObservationOffering/sos:time	min begin time and max end time of TimePeriods/TimeInstants on ObOffering times

Link between data and service:

<srv:operatesOn>
        <gmd:MD_DataIdentification uuid='identifier' xlink:href="link to xml document" xlink:title="Observation offering description"/>
</srv:operatesOn>

Root element:

• SOS = sos:Capabilities/sos:Contents/sos:ObservationOfferingList/sos:ObservationOffering

• Data metadata root node = /gmd:MD_Metadata
• Service identification node = gmd:identificationInfo/srv:SV_ServiceIdentification

Observation Offering Metadata

Element	ISO19115 equivalent	GetCapabilities element	Notes
Dataset metadata
Identifier	gmd:fileIdentifier/gco:CharacterString	« uuid »	Random uuid
Language	gmd:language/gco:characterString	« eng »	User Input. Default value « eng »
CharacterSet	gmd:CharacterSet/gmd:MD_CharacterSetCode	« utf8 »
HierarchyLevelCode	gmd:hierarchyLevel/gmd:MD_ScopeCode	codeListValue="dataset"
Contact	gmd:contact	cf contact mapping
Date stamp	gmd:dateStamp/gco:DateTime		Harvesting/Import date
Standard name	gmd:metadataStandardName/gco:CharacterString	« ISO 19115:2003/19139 »
Standard version	gmd:metadataStandardVertsion/gco:CharacterString	« 1.0 »
CRS	gmd:referenceSystemInfo/gmd:MD_ReferenceSystem/referenceSystemIdentifier/RS_Identifier/code	gml:srsName
dataQualityInfo	leave blank	none
Data Identification
Title	gmd:citation/gmd:CI_Citation/gmd:title/gco:CharacterString	gml:name[1]
Identifier	gmd:citation/gmd:CI_Citation/gmd:identifier/gmd:MD_identifier/gmd:code/(gmx:Anchor|gco:CharacterString)	gml:name	if gml:name has a codeSpace attribute use gmx:Anchor with href set to the codeSpace URI otherwise use gco:CharacterString
Date	gmd:citation/gmd:CI_Citation/gmd:date/gmd:CI_Date/gmd:date/gco:dateTime codeListValue=”revision”		Harvesting/Import date
Abstract	gmd:abstract/gco:CharacterString	gml:description
Purpose	gmd:purpose/gco:CharacterString	sos:intendedApplication	Concatenate multiple intended applications into one string separated by ','
Status	gmd:status/gmd:MD_ProgressCode	« onGoing » or « completed »	if gml:endPosition/@indeterminatePosition='now' assign <<onGoing>>, otherwise, use <<completed>>
Contact	gmd:pointOfContact	cf contact mapping
Keywords (theme)	gmd:descriptiveKeywords/gmd:MD_Keywords/gmd:keyword/gco:CharacterString	sos:observedProperty	gmd:MD_KeywordTypeCode codeList="​http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode" codeListValue="theme"
Keywords (place)	gmd:descriptiveKeywords/gmd:MD_Keywords/gmd:keyword/gco:CharacterString	sos:featureOfInterest	gmd:MD_KeywordTypeCode codeList="​http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode" codeListValue="place"
Topic Category	gmd:topicCategory/gmd:MD_TopicCategoryCode		User Input
Bounding box	gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicBoundingBox	gml:boundedBy/gml:Envelope	upper(nw) and lower (se) of lat/lon values on Observation Offering envelopes re-projected to WGS84
Temporal extent	gmd:extent/gmd:EX_Extent/gmd:temporalElement/gmd:EX_TemporalExtent	sos:time
Sensor	mcp:sensor/xlink:href	sos:procedure
Distribution
HTTP Get endpoint	gmd:linkage/gmd:URL	ows:Operation[@name='GetObservation']/ows:DCP/ows:HTTP/ows:Post/@xlink:href
	gmd:protocol/gco:CharacterString	« OGC:SOS-1.0.0-http-get-observation »
	gmd:name/gco:CharacterString	gml:name[1]	Name of the observation offering
	gmd:description:gcoCharacterString	gml:description
HTTP Post endpoint	gmd:linkage/gmd:URL	ows:Operation[@name='GetObservation']/ows:DCP/ows:HTTP/ows:Post/@xlink:href
	gmd:protocol/gco:CharacterString	« OGC:SOS-1.0.0-http-post-observation »
	gmd:name/gco:CharacterString	gml:name[1]	Name of the observation offering
	gmd:description:gcoCharacterString	gml:description
GetObservation requests for each response format	gmd:linkage/gmd:URL	ows:Operation[@name='GetObservation']/ows:DCP/ows:HTTP/ows:Get/@xlink:href/ + sos:observedProperty/@xlink:href + sos:responseFormat	One online resource section for each possible response format
	gmd:protocol/gco:CharacterString	« OGC:SOS-1.0.0-http-get-observation »
	gmd:name/gco:CharacterString	gml:name[1] + ' (' + sos:responseFormat + ')'	Name of the observation offering + response format
	gmd:description:gcoCharacterString	gml:description

Root element:

• SOS = sos:Capabilities/sos:Contents/sos:ObservationOfferingList/sos:ObservationOffering

• Data metadata root node = /gmd:MD_Metadata
• Identification node = gmd:identificationInfo/gmd:MD_DataIdentification
• Distribution node = gmd:distributionInfo/gmd:MD_Distribution/gmd:transferOptions/gmd:MD_DigitalTransferOptions/gmd:onLine/gmd:CI_OnlineResource

Backwards Compatibility Issues

None that I can see

New libraries added

No new libraries required

Risks

Participants

• Vitor Gonçalves - initial SOS Service to iso19119/iso19139 stylesheet
• Kate Roberts - mappings/review
• Simon Pigot - review
• Craig Jones - observation offering mapping/code (Marine and Climate Data Discovery and Access Project (MACDDAP)