Best Practices and Recommendations#
Community Approaches#
The INSPIRE, DGIWG and Linked Data communities (W3C DCAT) have adopted well-documented approaches for expressing conformance of data products with quality related data product specifications. These can be applied in the CEOS context to express compliance with CEOS-ARD Product Family Specifications [3] or other CEOS Specifications (e.g. WGISS Data Management and Stewardship Maturity Matrix conformance [4]).
Section 3.1.4 “Data quality info” of the INSPIRE Metadata Technical Guidance [5] provides specific guidelines on how to include a statement on the degree of conformity with the specifications against which its conformity has been evaluated. The same approach is used by DGIWG [2] in §5.4.2.4 “Conformance Result” of the “DGIWG Metadata Foundation” specification [6].
Section 14.2.1 of DCAT [7] contains general guidelines to be applied when expressing compliance with a standard in metadata:
Use the URI of the standard / specification. E.g., to express conformance of a dcat:CatalogRecord with DCAT, the URI to be used is https://www.w3.org/TR/vocab-dcat/.
Use the canonical, persistent URI. This is usually specified in the document itself. If you are in doubt, use the one included in the bibliographic citations for that standard / specification.
Use the non-versioned URI. If you need to express conformance with a specific version of the standard / specification, use both the un-versioned and the versioned URI
Application to CEOS-ARD#
CEOS-ARDMD-REC-0010 [Recommendation]
If a collection is conformant with all requirements of a CEOS-ARD data specification (threshold), it is recommended to include information on the conformance with the specification.
CEOS-ARDMD-REC-0020 [Recommendation]
If a collection is not yet conformant with all requirements of a CEOS-ARD data specification, it is recommended to include information on the conformance with the individual conformance classes (if any).
This approach is recommended by [8].
Alternatively, or in addition, a simple keyword-based identification of CEOS-ARD Product Families can be adoped as well, using codelist and codelist values. This approach is described as well.
Metadata Encoding#
In the following subsections, Best Practices are presented for encoding conformance results and controlled keywords in a number of widely used metadata formats.
ISO19139 Encoding#
This section describes best practices for ISO 19139 [9] and ISO 19139-1 [10] collection metadata encoding.
Section 3.1.4 “Data quality info” of the INSPIRE Metadata Technical Guidance [5] defines how to express conformance with a specification or a compliance class.
Conformance to a specification:
The URI of the actual specification is included as
xlink:hrefin the/gmd:title/gmx:anchorelement of thegmd:specification(TG Rec 1.11).
Conformance to a compliance class of a specification
The URI of the conformance class can be specified as
xlink:hrefin the/gmd:title/gmx:anchorelement of thegmd:specification(TG Rec 1.12).
Section 8.1.1 “Data quality info” recommendations 16 to 21 of the INSPIRE Data Specification on Orthoimagery – Technical Guidelines [8] can be adopted. They are similar to the above but state:
Conformance to a specification:
The URI of the specification is included as
xlink:hrefin thegmd:specification(Rec 21).
Conformance to a compliance class of a specification
The URI of the conformance class can be specified as
xlink:hrefin the/gmd:title/gmx:anchorelement of thegmd:specification(Rec 21).
Instead of including a complete citation of the specification, the following short notation is allowed according to [8] as well.
Example: 1.1
Documenting conformance with specification in ISO19139 metadata (without citation).
<gmd:DQ_ConformanceResult>
<gmd:specification xlink:href="https://ceos.org/ard/files/PFS/NRB/v5.5"/>
<gmd:explanation>
<gco:CharacterString>See the referenced specification</gco:CharacterString>
</gmd:explanation>
<gmd:pass>
<gco:Boolean>true</gco:Boolean>
</gmd:pass>
</gmd:DQ_ConformanceResult>
Possible results that can be expressed are:
true if conformant
false if not conformant
null (with nilReason) is not evaluated.
If conformance is not evaluated, the result should be as follows according to [5].
<gmd:pass gco:nilReason="unknown"/>
Example: 1.2
Documenting conformance with specification or conformance class in ISO19139 metadata (with citation).
Note that the specification URI is not inside the specification element but in a gmx:Anchor element as [5] allows adding there a reference to a citation document instead, so the two approaches are not consistent.
Data quality section as proposed in the INSPIRE Metadata Technical Guidance [5]
<?xml version="1.0" encoding="UTF-8"?>
<gmi:MI_Metadata xmlns:gmi="http://www.isotc211.org/2005/gmi"
xmlns:gco="http://www.isotc211.org/2005/gco"
xmlns:gmd="http://www.isotc211.org/2005/gmd"
xmlns:gmx="http://www.isotc211.org/2005/gmx"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.isotc211.org/2005/gmi ./gmi/gmi.xsd">
<gmd:dataQualityInfo xmlns:gmd="http://www.isotc211.org/2005/gmd">
<gmd:DQ_DataQuality>
<gmd:scope>
<gmd:DQ_Scope>
<gmd:level>
<gmd:MD_ScopeCode codeList="http://www.tc211.org/ISO19139/resources/codeList.xml#MD_ScopeCode"
codeListValue="series"/>
</gmd:level>
</gmd:DQ_Scope>
</gmd:scope>
<gmd:report>
<gmd:DQ_ConceptualConsistency>
<gmd:result>
<gmd:DQ_ConformanceResult>
<gmd:specification>
<gmd:CI_Citation>
<gmd:title>
<gmx:Anchor xlink:href="https://ceos.org/ard/files/PFS/NRB/v5.5">CEOS-ARD Product Family Specification: Normalised Radar Backscatter</gmx:Anchor>
</gmd:title>
<gmd:date>
<gmd:CI_Date>
<gmd:date>
<gco:Date>2021-10-14</gco:Date>
</gmd:date>
<gmd:dateType>
<gmd:CI_DateTypeCode codeList="https://standards.iso.org/iso/19139/resources/gmxCodelists.xml#CI_DateTypeCode"
codeListValue="publication"/>
</gmd:dateType>
</gmd:CI_Date>
</gmd:date>
</gmd:CI_Citation>
</gmd:specification>
<gmd:explanation>
<gco:CharacterString>See the referenced specification</gco:CharacterString>
</gmd:explanation>
<gmd:pass>
<gco:Boolean>true</gco:Boolean>
</gmd:pass>
</gmd:DQ_ConformanceResult>
</gmd:result>
</gmd:DQ_DomainConsistency>
</gmd:report>
</gmd:DQ_DataQuality>
</gmd:dataQualityInfo>
CEOS-ARDMD-REC-1010 [Recommendation]
Collection metadata records in ISO19139(-2) format should advertise conformance status with respect to CEOS-ARD PFS using a citation element with reference to the document URI or conformance class URI as shown in example 1.2.
Example: 1.3
Documenting conformance with specification ISO19139 metadata (with keywords).
<gmd:descriptiveKeywords xmlns:gmx="http://www.isotc211.org/2005/gmx">
<gmd:MD_Keywords>
<gmd:keyword>
<gmx:Anchor xlink:href="https://ceos.org/ard/metadata-codelists/PFS/NRB">Normalised Radar Backscatter</gmx:Anchor>
</gmd:keyword>
<gmd:thesaurusName>
<gmd:CI_Citation>
<gmd:title>
<gmx:Anchor xlink:href="https://ceos.org/ard/metadata-codelists/PFS">CEOS-ARD Product Family Specification</gmx:Anchor>
</gmd:title>
<gmd:date/>
</gmd:CI_Citation>
</gmd:thesaurusName>
</gmd:MD_Keywords>
</gmd:descriptiveKeywords>
ISO19115-3 Encoding#
This section describes best practices for ISO 19115-3 [11] collection metadata encoding. It relies on the ISO19157-2 [12] XML schema implementation for Data Quality.
Example: 2.1
Documenting conformance with specification or conformance class in ISO19115-3 metadata (without citation).
<?xml version="1.0" encoding="UTF-8"?>
<mdb:MD_Metadata xmlns:mdb="http://standards.iso.org/iso/19115/-3/mdb/1.0"
xmlns:gco="http://standards.iso.org/iso/19115/-3/gco/1.0"
xmlns:mcc="http://standards.iso.org/iso/19115/-3/mcc/1.0"
xmlns:mdq="http://standards.iso.org/iso/19157/-2/mdq/1.0"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<mdb:dataQualityInfo>
<mdq:DQ_DataQuality>
<mdq:scope>
<mcc:MD_Scope>
<mcc:level>
<mcc:MD_ScopeCode codeList="http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_19139_Schemas/resources/codelist/gmxCodelists.xml#MD_ScopeCode"
codeListValue="series"/>
</mcc:level>
</mcc:MD_Scope>
</mdq:scope>
<mdq:report>
<mdq:DQ_DomainConsistency>
<mdq:result>
<mdq:DQ_ConformanceResult>
<mdq:specification xlink:href="https://ceos.org/ard/files/PFS/NRB/v5.5/CARD4L-PFS_NRB_v5.5.pdf"/>
<mdq:explanation>
<gco:CharacterString>See the referenced specification</gco:CharacterString>
</mdq:explanation>
<mdq:pass>
<gco:Boolean>true</gco:Boolean>
</mdq:pass>
</mdq:DQ_ConformanceResult>
</mdq:result>
</mdq:DQ_DomainConsistency>
</mdq:report>
</mdq:DQ_DataQuality>
</mdb:dataQualityInfo>
</mdb:MD_Metadata>
Example: 2.2
Documenting conformance with specification or conformance class in ISO19115-3 metadata (with citation).
<?xml version="1.0" encoding="UTF-8"?>
<mdb:MD_Metadata xmlns:mdb="http://standards.iso.org/iso/19115/-3/mdb/1.0"
xmlns:cit="http://standards.iso.org/iso/19115/-3/cit/1.0"
xmlns:gco="http://standards.iso.org/iso/19115/-3/gco/1.0"
xmlns:gcx="http://standards.iso.org/iso/19115/-3/gcx/1.0"
xmlns:mcc="http://standards.iso.org/iso/19115/-3/mcc/1.0"
xmlns:mdq="http://standards.iso.org/iso/19157/-2/mdq/1.0"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<mdb:dataQualityInfo>
<mdq:DQ_DataQuality>
<mdq:scope>
<mcc:MD_Scope>
<mcc:level>
<mcc:MD_ScopeCode codeList="http://www.tc211.org/ISO19139/resources/codeList.xml#MD_ScopeCode"
codeListValue="series"/>
</mcc:level>
</mcc:MD_Scope>
</mdq:scope>
<mdq:report>
<mdq:DQ_DomainConsistency>
<mdq:result>
<mdq:DQ_ConformanceResult>
<mdq:specification>
<cit:CI_Citation>
<cit:title>
<gcx:Anchor xlink:href="https://ceos.org/ard/files/PFS/NRB/v5.5">CEOS-ARD Product Family Specification: Normalised Radar Backscatter</gcx:Anchor>
</cit:title>
<cit:date>
<cit:CI_Date>
<cit:date>
<gco:Date>2021-10-14</gco:Date>
</cit:date>
<cit:dateType>
<cit:CI_DateTypeCode codeList="https://standards.iso.org/iso/19115/resources/Codelists/cat/codelists.xml#CI_DateTypeCode"
codeListValue="publication"/>
</cit:dateType>
</cit:CI_Date>
</cit:date>
</cit:CI_Citation>
</mdq:specification>
<mdq:explanation>
<gco:CharacterString>See the referenced specification</gco:CharacterString>
</mdq:explanation>
<mdq:pass>
<gco:Boolean>true</gco:Boolean>
</mdq:pass>
</mdq:DQ_ConformanceResult>
</mdq:result>
</mdq:DQ_DomainConsistency>
</mdq:report>
</mdq:DQ_DataQuality>
</mdb:dataQualityInfo>
</mdb:MD_Metadata>
CEOS-ARDMD-REC-2010 [Recommendation]
Collection metadata records in ISO19115-3 [11] format should advertise conformance status with respect to CEOS-ARD PFS using a citation element with reference to the document URI or conformance class URI as shown in example 2.2.
Example: 2.3
Documenting conformance with specification in ISO19115-3 metadata with additional information about evaluation method, self assessment, peer review etc.
<mdb:dataQualityInfo>
<mdq:DQ_DataQuality>
<mdq:scope>
<mcc:MD_Scope>
<mcc:level>
<mcc:MD_ScopeCode codeList="http://www.tc211.org/ISO19139/resources/codeList.xml#MD_ScopeCode" codeListValue="series"/>
</mcc:level>
</mcc:MD_Scope>
</mdq:scope>
<mdq:report>
<mdq:DQ_ConceptualConsistency>
<mdq:measure>
<mdq:DQ_MeasureReference>
<mdq:measureIdentification>
<mcc:MD_Identifier>
<mcc:authority>
<cit:CI_Citation>
<cit:title>
<gco:CharacterString>International Organization for Standardization</gco:CharacterString>
</cit:title>
<cit:alternateTitle>
<gco:CharacterString>ISO</gco:CharacterString>
</cit:alternateTitle>
<cit:date/>
</cit:CI_Citation>
</mcc:authority>
<mcc:code>
<gco:CharacterString>101</gco:CharacterString>
</mcc:code>
<mcc:codeSpace>
<gco:CharacterString>https://standards.isotc211.org/19157/-3/1/dqc/content/qualityMeasure/</gco:CharacterString>
</mcc:codeSpace>
</mcc:MD_Identifier>
</mdq:measureIdentification>
<mdq:nameOfMeasure>
<gco:CharacterString>Data product specification passed</gco:CharacterString>
</mdq:nameOfMeasure>
<mdq:measureDescription>
<gco:CharacterString>Indication that all requirements in the referred data product specification are fulfilled.</gco:CharacterString>
</mdq:measureDescription>
</mdq:DQ_MeasureReference>
</mdq:measure>
<mdq:evaluationMethod>
<mdq:DQ_FullInspection>
<mdq:evaluationMethodDescription>
<gco:CharacterString>CEOS WGCV evaluation</gco:CharacterString>
</mdq:evaluationMethodDescription>
<mdq:evaluationProcedure>
<cit:CI_Citation>
<cit:title>
<gco:CharacterString>CEOS-ARD Normalised Radar Backscatter</gco:CharacterString>
</cit:title>
<cit:date>
<cit:CI_Date>
<cit:date>
<gco:Date>2021-10-14</gco:Date>
</cit:date>
<cit:dateType>
<cit:CI_DateTypeCode codeList="https://standards.iso.org/iso/19115/resources/Codelists/cat/codelists.xml#CI_DateTypeCode"
codeListValue="publication"/>
</cit:dateType>
</cit:CI_Date>
</cit:date>
<cit:edition>
<gco:CharacterString>5.5</gco:CharacterString>
</cit:edition>
<cit:onlineResource>
<cit:CI_OnlineResource>
<cit:linkage>
<gco:CharacterString>https://ceos.org/ard/files/PFS/NRB/v5.5</gco:CharacterString>
</cit:linkage>
<cit:name>
<gco:CharacterString>Specification</gco:CharacterString>
</cit:name>
<cit:function>
<cit:CI_OnLineFunctionCode codeList="http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_19139_Schemas/resources/codelist/ML_gmxCodelists.xml#CI_OnLineFunctionCode"
codeListValue="information"/>
</cit:function>
</cit:CI_OnlineResource>
</cit:onlineResource>
<cit:onlineResource>
<cit:CI_OnlineResource>
<cit:linkage>
<gco:CharacterString>https://ceos.org/ard/files/Self%20Assessments/NRB/v5.5/NovaSAR_CSIRO_SelfAssessment.zip</gco:CharacterString>
</cit:linkage>
<cit:name>
<gco:CharacterString>Self assessment</gco:CharacterString>
</cit:name>
<cit:function>
<cit:CI_OnLineFunctionCode codeList="http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_19139_Schemas/resources/codelist/ML_gmxCodelists.xml#CI_OnLineFunctionCode"
codeListValue="information"/>
</cit:function>
</cit:CI_OnlineResource>
</cit:onlineResource>
<cit:onlineResource>
<cit:CI_OnlineResource>
<cit:linkage>
<gco:CharacterString>https://ceos.org/ard/files/Peer%20Reviews/NRB/v5.5/NovaSAR_WGCVEval.zip</gco:CharacterString>
</cit:linkage>
<cit:name>
<gco:CharacterString>Peer review</gco:CharacterString>
</cit:name>
<cit:function>
<cit:CI_OnLineFunctionCode codeList="http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_19139_Schemas/resources/codelist/ML_gmxCodelists.xml#CI_OnLineFunctionCode"
codeListValue="information"/>
</cit:function>
</cit:CI_OnlineResource>
</cit:onlineResource>
</cit:CI_Citation>
</mdq:evaluationProcedure>
</mdq:DQ_FullInspection>
</mdq:evaluationMethod>
<mdq:result>
<mdq:DQ_ConformanceResult>
<mdq:specification>
<cit:CI_Citation>
<cit:title>
<gcx:Anchor xlink:href="https://ceos.org/ard/files/PFS/NRB/v5.5">CEOS-ARD Product Family Specification: Normalised Radar Backscatter</gcx:Anchor>
</cit:title>
<cit:date>
<cit:CI_Date>
<cit:date>
<gco:Date>2021-10-14</gco:Date>
</cit:date>
<cit:dateType>
<cit:CI_DateTypeCode codeList="https://standards.iso.org/iso/19115/resources/Codelists/cat/codelists.xml#CI_DateTypeCode"
codeListValue="publication"/>
</cit:dateType>
</cit:CI_Date>
</cit:date>
</cit:CI_Citation>
</mdq:specification>
<mdq:explanation>
<gco:CharacterString>See the referenced specification</gco:CharacterString>
</mdq:explanation>
<mdq:pass>
<gco:Boolean>true</gco:Boolean>
</mdq:pass>
</mdq:DQ_ConformanceResult>
</mdq:result>
</mdq:DQ_ConceptualConsistency>
</mdq:report>
</mdq:DQ_DataQuality>
</mdb:dataQualityInfo>
Example: 2.4
Documenting conformance with specification in ISO19115-3 metadata (with keywords).
<mri:descriptiveKeywords>
<mri:MD_Keywords>
<mri:keyword>
<gcx:Anchor xlink:href="https://ceos.org/ard/metadata-codelists/PFS/NRB">Normalised Radar Backscatter</gcx:Anchor>
</mri:keyword>
<mri:thesaurusName>
<cit:CI_Citation>
<cit:title>
<gcx:Anchor xlink:href="https://ceos.org/ard/metadata-codelists/PFS">CEOS-ARD Product Family Specification</gcx:Anchor>
</cit:title>
<cit:date/>
</cit:CI_Citation>
</mri:thesaurusName>
</mri:MD_Keywords>
</mri:descriptiveKeywords>
Example files: - novasar_l2ard_hh_hv_1.xml - novasar_l2ard_hh_hv_2.xml
ISO19115-4 Encoding#
This section describes best practices for ISO 19115-4 [13] collection metadata encoding.
Example: 3.1
Documenting conformance with specification or conformance class in ISO19115-4 [13] metadata (with citation).
{
"dataQualityInfo": [
{
"scope": {
"level": "series"
},
"report": [
{
"measure": {
"measureIdentification": {
"code": "101",
"codeSpace": "https://standards.isotc211.org/19157/-3/1/dqc/content/qualityMeasure/"
},
"nameOfMeasure": ["data product specification passed"],
"measureDescription": "Indication that all requirements in the referred data product specification are fulfilled."
},
"result": [
{
"pass": true,
"specification": {
"date": {
"publication": "2021-10-14"
},
"identifier": [
{
"code": "https://ceos.org/ard/files/PFS/SR/v5.0.1",
"codeSpace": "https://ceos.org/ard"
}
],
"edition": "5.0",
"title": "CEOS-ARD Product Family Specification: Surface Reflectance"
},
"type": "ConformanceResult",
"explanation": "See the referenced specification"
}
],
"type": "DomainConsistency"
}
]
}
]
}
Example: 3.2
Documenting conformance with specification in ISO19115-4 metadata with additional information about evaluation method, self assessment, peer review, sampling ratio etc.
{
"dataQualityInfo": [
{
"scope": {
"level": "series"
},
"report": [
{
"measure": {
"measureIdentification": {
"code": "101",
"codeSpace": "https://standards.isotc211.org/19157/-3/1/dqc/content/qualityMeasure/"
},
"nameOfMeasure": ["data product specification passed"],
"measureDescription": "Indication that all requirements in the referred data product specification are fulfilled."
},
"result": [{
"pass": true,
"specification": {
"date": {
"publication": "2021-10-14"
},
"identifier": [
{
"code": "https://ceos.org/ard/files/PFS/NRB/v5.5",
"codeSpace": "tbd"
}
],
"edition": "5.5",
"title": "CEOS-ARD Product Family Specification: Normalised Radar Backscatter"
},
"type": "ConformanceResult",
"explanation": "See the referenced specification"
}
],
"evaluationMethod": [{
"referenceDoc": [],
"evaluationProcedure": {
"editionDate": "2021-10-14",
"edition": "5.5",
"onlineResource": [{
"name": "Specification",
"function": "information",
"linkage": "https://ceos.org/ard/files/PFS/NRB/v5.5/CARD4L-PFS_NRB_v5.5.pdf"
}, {
"name": "Self assessment",
"function": "information",
"linkage": "https://ceos.org/ard/files/Self20Assessments/NRB/v5.5/Opera%20RTC%20Sentinel-1%20self-assessment.zip"
}, {
"name": "Peer review",
"function": "information",
"linkage": "https://ceos.org/ard/files/Peer%20Reviews/NRB/v5.5/NovaSAR_WGCVEval.zip"
}
],
"title": "CEOS-ARD Normalised Radar Backscatter"
},
"samplingRatio": "unknown.",
"samplingScheme": "See Peer review report.",
"lotDescription": "31 PFS metadata items. See ee Peer review report for additional detail.",
"type": "SampleBasedInspection",
"evaluationMethodDescription": "CEOS WGCV evaluation"
}
]
}
]
}
]
}
CEOS-ARDMD-REC-3010 [Recommendation]
Collection metadata records in ISO19115-4 [13] format should advertise conformance status with respect to CEOS-ARD PFS using a citation element with reference to the document URI or conformance class URI as shown in example 3.1.
Example: 3.3
Documenting conformance with specification in ISO19115-4 metadata (with keywords).
{
"identificationInfo": {
"defaultLocale": {
"language": "eng",
"characterEncoding": "utf8"
},
"extent": [{"geographicElement": [{
"northBoundLatitude": 38.42053289934906,
"southBoundLatitude": -55.94470669421993,
"type": "EX_GeographicBoundingBox",
"westBoundLongitude": -62.87262834116111,
"eastBoundLongitude": 173.246741777445
}]}],
"descriptiveKeywords": [{
"thesaurusName": {
"title": "CEOS-ARD Product Family Specification"
},
"keyword": ["Normalised Radar Backscatter"]
}],
"citation": {
"date": {"creation": "2025-10-20"},
"title": "novasar_l2ard_hh_hv"
},
"abstract": "NovaSAR-1 CEOS-ARD (level 2) HH,HV polarizations"
}
}
Example files: - novasar_l2ard_hh_hv.json
STAC Encoding#
This section describes best practices for STAC [14] collection metadata encoding.
The proposed encoding uses the draft STAC CEOS-ARD Extension [15]
{
"stac_version": "1.0.0",
"type": "Collection",
"title": "EnMAP L2A HSI Products",
"ceosard:specification": "SR",
"ceosard:type": "optical",
"ceosard:specification_version": "5.0",
"links": [
{
"rel": "ceos-ard-specification",
"href": "https://ceos.org/ard/files/PFS/SR/v5.0/CARD4L_Product_Family_Specification_Surface_Reflectance-v5.0.pdf",
"type": "application/pdf",
"title": "CEOS-ARD Product Family Specification for Surface Reflectance (PDF)"
},
{
"rel": "ceos-ard-assessment",
"href": "https://ceos.org/ard/files/Self%20Assessments/SR/v5.0/Response_Review_comments_EnMAP_CARD4L_Product_Family_Specification_Surface_Reflectance-v5.pdf",
"type": "application/pdf",
"title": "Peer assessment"
},
],
"id": "ENMAP_HSI_L2A",
"stac_extensions": [
"https://stac-extensions.github.io/ceos-ard/v0.2.0/schema.json"
]
}
Warning
The STAC CEOS-ARD Extension [15] properties ceosard:specification and specification_version do currently not allow to express that a collection is conformant with more than one CEOS-ARD Product Famility Specification.
TBD: could the “document identifier” redirect to the PDF to not have the detailed PDF filename to identify the specification ?
"links": [
{
"rel": "ceos-ard-specification",
"href": "https://ceos.org/ard/files/PFS/SR/v5.0",
"type": "text/html",
"title": "Surface Reflectance (CARD4L-SR)"
}
]
Alternatively, the lightweight approach with controlled keywords can be used.
{
"stac_version": "1.0.0",
"type": "Collection",
"title": "EnMAP L2A HSI Products",
"themes": [{
"concepts": [{
"id": "SR",
"title": "Surface Reflectance",
"url": "https://ceos.org/ard/metadata-codelists/PFS/SR"
}],
"scheme": "https://ceos.org/ard/metadata-codelists/PFS"
}],
"id": "ENMAP_HSI_L2A",
"stac_extensions": [
"https://stac-extensions.github.io/themes/v1.0.0/schema.json"
]
}
CEOS-ARDMD-REC-4010 [Recommendation]
Collection metadata records in STAC [14] format should advertise conformance status with respect to CEOS-ARD PFS using the STAC CEOS-ARD Extension [15] with reference to the document URI as shown in example 4.1.
Example files: - ENMAP_HSI_L2A.json
DIF10 Encoding#
This section describes best practices for DIF10 [17] collection metadata encoding.
Example: 5.1
Documenting conformance with specification or conformance class in DIF10 [17] metadata.
TBD
Example: 5.3
Documenting conformance with specification in DIF10 [17] metadata (with keywords).
<?xml version="1.0" encoding="UTF-8"?>
<DIF
xmlns="http://gcmd.gsfc.nasa.gov/Aboutus/xml/dif/"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://gcmd.gsfc.nasa.gov/Aboutus/xml/dif/ https://git.earthdata.nasa.gov/projects/EMFD/repos/dif-schemas/raw/10.x/dif_v10.2.xsd">
<Entry_ID>
<Short_Name>novasar_l2ard_hh_hv</Short_Name>
<Version>NA</Version>
</Entry_ID>
<Extended_Metadata>
<Metadata>
<Group>org.ceos</Group>
<Name>https://ceos.org/ard/metadata-codelists/PFS</Name>
<Value>NRB</Value>
<Value>Normalised Radar Backscatter</Value>
</Metadata>
</Extended_Metadata>
</DIF>
UMM-JSON Encoding#
This section describes best practices for UMM-JSON [18] collection metadata encoding.
Example: 6.1
Documenting conformance with specification or conformance class in UMM-JSON metadata.
Example: 6.3
Documenting conformance with specification in UMM-JSON [18] metadata (with keywords).
{
"MetadataSpecification": {
"URL": "https://cdn.earthdata.nasa.gov/umm/collection/v1.18.6",
"Name": "UMM-C",
"Version": "1.18.6"
},
"ProcessingLevel": {
"Id": "2"
},
"CollectionProgress": "COMPLETE",
"DOI": {
"DOI": "NA"
},
"ShortName": "novasar_l2ard_hh_hv",
"Version": "1",
"EntryTitle": "NovaSAR-1 CEOS-ARD (level 2) HH,HV polarizations",
"Abstract": "NovaSAR-1 CEOS-ARD (level 2) HH,HV polarizations",
"DataLanguage": "eng",
"DataDates": [
{
"Date": "2026-04-22T00:00:00.000Z",
"Type": "CREATE"
}
],
"ScienceKeywords": [
{
"Category": "EARTH SCIENCE",
"Topic": "SPECTRAL/ENGINEERING",
"Term": "VISIBLE WAVELENGTHS"
}
],
"SpatialExtent": {
"GranuleSpatialRepresentation": "NO_SPATIAL",
"HorizontalSpatialDomain": {
"Geometry": {
"CoordinateSystem": "CARTESIAN",
"BoundingRectangles": [
{
"WestBoundingCoordinate": -62.87262834116111,
"NorthBoundingCoordinate": 38.42053289934906,
"EastBoundingCoordinate": 173.246741777445,
"SouthBoundingCoordinate": -55.94470669421993
}
]
}
}
},
"TemporalExtents": [
{
"RangeDateTimes": [
{
"BeginningDateTime": "2019-11-02T02:32:55.000Z",
"EndingDateTime": "2025-10-08T12:05:22.999Z"
}
]
}
],
"DataCenters": [
{
"ShortName": "CSIRO",
"Roles": [
"DISTRIBUTOR"
]
}
],
"Platforms": [
{
"ShortName": "NOVASAR-1",
"Instruments": [
{
"ShortName": "s-band sar"
}
]
}
],
"AdditionalAttributes": [
{
"Value": "https://ceos.org/ard/metadata-codelists/PFS/NRB/5.5",
"Name": "https://ceos.org/ard/metadata-codelists/PFS",
"Description": "CEOS-ARD Product Family Specification",
"DataType": "STRING"
},
{
"Value": "https://ceos.org/ard/metadata-codelists/PFS/NRB",
"Name": "https://ceos.org/ard/metadata-codelists/PFS",
"Description": "CEOS-ARD Product Family Specification",
"DataType": "STRING"
}
]
}
GeoDCAT-AP Encoding#
This section describes best practices for GeoDCAT-AP [19] collection metadata encoding based on DCAT [7]. The encoding is valid for the RDF/XML, Turtle and JSON-LD serialisations. The proposed encoding is derived from the guidance in the ISO19139 to DCAT-AP mappings.
Additional information is available at:
Example: 7.1
Documenting conformance with specification or conformance class in GeoDCAT-AP metadata.
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dct="http://purl.org/dc/terms/"
xmlns:prov="http://www.w3.org/ns/prov#"
xmlns:dcat="http://www.w3.org/ns/dcat#"
xmlns:xsd="http://www.w3.org/2001/XMLSchema#">
<dcat:Dataset rdf:about="https://fedeo.ceos.org/collections/novasar_l2ard_hh_hv">
<dct:conformsTo>
<dct:Standard rdf:about="https://ceos.org/ard/files/PFS/NRB/v5.5">
<dct:title>CEOS-ARD Product Family Specification: Normalised Radar Backscatter</dct:title>
<dct:identifier>https://ceos.org/ard/files/PFS/NRB/v5.5</dct:identifier>
<dct:hasVersion>5.5</dct:hasVersion>
<rdfs:seeAlso rdf:resource="https://ceos.org/ard/files/PFS/NRB/v5.5/CARD4L-PFS_NRB_v5.5.pdf"/>
</dct:Standard>
</dct:conformsTo>
</dcat:Dataset>
</rdf:RDF>
Example: 7.2
Documenting conformance with specification or conformance class in GeoDCAT-AP metadata (without citation).
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dct="http://purl.org/dc/terms/"
xmlns:prov="http://www.w3.org/ns/prov#"
xmlns:dcat="http://www.w3.org/ns/dcat#"
xmlns:xsd="http://www.w3.org/2001/XMLSchema#">
<dcat:Dataset rdf:about="https://fedeo.ceos.org/collections/novasar_l2ard_hh_hv">
<prov:wasUsedBy>
<prov:Activity>
<prov:qualifiedAssociation rdf:parseType="Resource">
<prov:hadPlan rdf:parseType="Resource">
<!-- Specification -->
<prov:wasDerivedFrom rdf:resource="https://ceos.org/ard/files/PFS/NRB/v5.5"/>
</prov:hadPlan>
</prov:qualifiedAssociation>
<!-- Conformance result / conformity degree -->
<prov:generated rdf:parseType="Resource">
<dct:type rdf:resource="http://inspire.ec.europa.eu/metadata-codelist/DegreeOfConformity/conformant"/>
<dct:description xml:lang="en">See the referenced specification</dct:description>
</prov:generated>
</prov:Activity>
</prov:wasUsedBy>
</dcat:Dataset>
</rdf:RDF>
The same example in Turtle is shown below.
@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix prov: <http://www.w3.org/ns/prov#> .
@prefix dc: <http://purl.org/dc/terms/> .
<https://fedeo.ceos.org/collections/novasar_l2ard_hh_hv>
a dcat:Dataset ;
prov:wasUsedBy [
a prov:Activity ;
prov:qualifiedAssociation [ prov:hadPlan [ prov:wasDerivedFrom <https://ceos.org/ard/files/PFS/NRB/v5.5> ] ] ;
prov:generated [
dc:type <http://inspire.ec.europa.eu/metadata-codelist/DegreeOfConformity/conformant> ;
dc:description "See the referenced specification"@en
]
] .
Possible values are defined in the INSPIRE codelist:
conformant
notConformant
notEvaluated
Example: 7.3
Documenting conformance with specification or conformance class in GeoDCAT-AP metadata (with citation).
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dct="http://purl.org/dc/terms/"
xmlns:prov="http://www.w3.org/ns/prov#"
xmlns:dcat="http://www.w3.org/ns/dcat#"
xmlns:xsd="http://www.w3.org/2001/XMLSchema#">
<dcat:Dataset rdf:about="https://fedeo.ceos.org/collections/novasar_l2ard_hh_hv">
<prov:wasUsedBy>
<prov:Activity>
<prov:qualifiedAssociation rdf:parseType="Resource">
<prov:hadPlan rdf:parseType="Resource">
<!-- Specification -->
<prov:wasDerivedFrom>
<rdf:Description rdf:about="https://ceos.org/ard/files/PFS/NRB/v5.5">
<dct:title xml:lang="en">CEOS-ARD Product Family Specification: Normalised Radar Backscatter</dct:title>
<dct:hasVersion>5.5</dct:hasVersion>
<dct:issued rdf:datatype="http://www.w3.org/2001/XMLSchema#date">2010-12-08</dct:issued>
<dct:publisher rdf:resource="http://dbpedia.org/resource/Committee_on_Earth_Observation_Satellites"/>
</rdf:Description>
</prov:wasDerivedFrom>
</prov:hadPlan>
</prov:qualifiedAssociation>
<!-- Conformance result / conformity degree -->
<prov:generated rdf:parseType="Resource">
<dct:type rdf:resource="http://inspire.ec.europa.eu/metadata-codelist/DegreeOfConformity/conformant"/>
<dct:description xml:lang="en">See the referenced specification</dct:description>
</prov:generated>
</prov:Activity>
</prov:wasUsedBy>
</dcat:Dataset>
</rdf:RDF>
The same example in Turtle is shown below.
@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix prov: <http://www.w3.org/ns/prov#> .
@prefix dc: <http://purl.org/dc/terms/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
<https://fedeo.ceos.org/collections/novasar_l2ard_hh_hv>
a dcat:Dataset ;
prov:wasUsedBy [
a prov:Activity ;
prov:qualifiedAssociation [ prov:hadPlan [ prov:wasDerivedFrom <https://ceos.org/ard/files/PFS/NRB/v5.5> ] ] ;
prov:generated [
dc:type <http://inspire.ec.europa.eu/metadata-codelist/DegreeOfConformity/conformant> ;
dc:description "See the referenced specification"@en
]
] .
<https://ceos.org/ard/files/PFS/NRB/v5.5>
dc:title "CEOS-ARD Product Family Specification: Normalised Radar Backscatter"@en ;
dc:hasVersion "5.5" ;
dc:issued "2010-12-08"^^xsd:date ;
dc:publisher <http://dbpedia.org/resource/Committee_on_Earth_Observation_Satellites> .
Example: 7.4
Documenting conformance with specification in GeoDCAT-AP [19] metadata (with keywords).
{
"@context": {},
"@type": "dcat:Dataset",
"dct:type": "http://inspire.ec.europa.eu/metadata-codelist/ResourceType/series",
"dct:identifier": "novasar_l2ard_hh_hv",
"dct:description": "NovaSAR-1 CEOS-ARD (level 2) HH,HV polarizations",
"dcat:theme": [{
"skos:prefLabel": "Normalised Radar Backscatter",
"@type": "skos:Concept",
"@id": "https://ceos.org/ard/metadata-codelists/PFS/NRB",
"skos:inScheme": "https://ceos.org/ard/metadata-codelists/PFS"
}],
"@id": "https://emc.spacebel.be/collections/novasar_l2ard_hh_hv",
"dct:title": "novasar_l2ard_hh_hv"
}
CEOS-ARDMD-REC-7010 [Recommendation]
Collection metadata records in GeoDCAT-AP [19] format (in RDF/XML, Turtle or JSON-LD serialisation) should advertise conformance status with respect to CEOS-ARD PFS using a citation element with dct:title and reference to the document URI or conformance class URI (rdf:Description) as shown in example 7.3.
OGC 17-084r1 Encoding#
This section describes best practices for OGC 17-084r1 [20] collection metadata encoding.
Example: 8.1
Documenting conformance with specification or conformance class in OGC 17-084r1 [20] metadata.
{
"geometry": {
},
"id": "https://fedeo.ceos.org/collections/novasar_l2ard_hh_hv",
"type": "Feature",
"properties": {
"date": "2019-11-02T02:32:55.000Z/2025-10-08T12:05:22.999Z",
"identifier": "novasar_l2ard_hh_hv",
"wasUsedBy": [{
"generated": {
"degree": "http://inspire.ec.europa.eu/metadata-codelist/DegreeOfConformity/conformant",
"description": "See the referenced specification",
"type": "Entity"
},
"qualifiedAssociation": {
"hadPlan": {
"wasDerivedFrom": {
"type": "Standard",
"issued": "2021-10-14T00:00:00.00Z"
},
"type": "Plan"
},
"type": "Association"
},
"type": "Activity"
}],
"contactPoint": [{
"hasAddress": {
"postal-code": "ACT 2601",
"street-address": "Building 101, Clunies Ross Street",
"locality": "Black Mountain",
"country-name": "Australia"
},
"phone": "tel:+61395452176",
"name": "CSIRO",
"type": "Organization",
"uri": "www.csiro.au"
}],
"kind": "http://purl.org/dc/dcmitype/Collection",
"created": "2025-10-20T00:00:00.000Z",
"abstract": {"text/plain": "NovaSAR-1 CEOS-ARD (level 2) HH,HV polarizations"},
"title": "novasar_l2ard_hh_hv",
"links": {
"previews": [{
"href": "https://eo-data.csiro.au/projects/easi-thumbnails/novasar_l2ard_hh_hv/2019/11/CEOS-ARD_NRB_v5_5_NovaSAR_01_7940_scd_29_191102_023255_HH_HV_A_R-ql.png",
"title": "graphic overview",
"type": "image/png"
}],
"alternates": [
]
},
"categories": [{
"scheme": "https://ceos.org/ard/metadata-codelists/PFS",
"term": "https://ceos.org/ard/metadata-codelists/PFS/NRB",
"label": "Normalised Radar Backscatter"
}],
"isPrimaryTopicOf": {
"created": "2025-10-20T00:00:00.00Z",
"conformsTo": {
"versionInfo": "2005/Cor.1:2006",
"type": "Standard",
"title": "ISO19115"
},
"type": "CatalogRecord",
"lang": "en",
"updated": "2025-10-20T00:00:00.00Z"
},
"updated": "2025-10-20T00:00:00.000Z"
}
}
Example: 8.2
Documenting conformance with specification in OGC 17-084r1 [20] metadata using controlled keywords.
"categories": [
{
"scheme": "https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/platforms",
"term": "https://gcmd.earthdata.nasa.gov/kms/concept/edd3cc77-31a1-4ed3-8da4-64a9554aa6fa",
"label": "EnMAP"
},
{
"scheme": "https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/instruments",
"term": "https://gcmd.earthdata.nasa.gov/kms/concept/5455b670-66d7-417b-b616-877b94caafe0",
"label": "HSI"
},
{
"scheme": "https://ceos.org/ard/metadata-codelists/PFS",
"term": "https://ceos.org/ard/metadata-codelists/PFS/SR",
"label": "Surface Reflectance"
}
]
CEOS-ARDMD-REC-8010 [Recommendation]
Collection metadata records in [20] format should advertise conformance status with respect to CEOS-ARD PFS using the STAC CEOS-ARD Extension [15] with reference to the document URI as shown in example 8.1.
Example files: - novasar_l2ard_hh_hv.json
Traceability#
TBD: mapping of proposed requirements to source documents and metadata formats.