Data Discovery (DIF)
From Earth Science Information Partners (ESIP)
The spirals below provide required and highly recommended attributes for NASA's Directory Interchange Format (DIF). Where compatible the spirals provide xpath references for DIF, ECHO, ECS, DCAT, ISO, ISO-1 and FGDC documentation dialects.
DIF for Data Discovery - Required
The Directory Interchange Format (DIF) is a NASA metadata format used to create directory entries that describe scientific data sets. The attributes in the spiral below are required by the DIF standard. Additonal documentation is available via the following online references:
Source: Interactive Write a DIF Guide DIF standard specification
| Concept | Description | Dialect (Fit) Paths |
|---|---|---|
| Metadata Identifier | A phrase or string which uniquely identifies the metadata file/record. | DIF /dif:DIF/dif:Entry_Id ISO /*/gmd:fileIdentifier/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:metadataIdentifier/mcc:MD_Identifier |
| Resource Title | A short description of the resource. The title should be descriptive enough so that when a user is presented with a list of titles the general content of the data set can be determined. | DIF /dif:DIF/dif:Entry_Title DIF /dif:DIF/dif:Data_Set_Citation/dif:Dataset_Title ECHO /*/echo:ShortName>/*/echo:LongName ECS /*/ecs:ShortName > /*/ecs:LongName DCAT dct:title FGDC /fgdc:metadata/fgdc:idinfo/fgdc:citation/fgdc:citeinfo/fgdc:title ISO /*/gmd:identificationInfo/*/gmd:citation/gmd:CI_Citation/gmd:title/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:citation/cit:CI_Citation/cit:title/gco:CharacterString |
| Keyword | A word or phrase that describes some aspect of a resource. Can be one of several types. Note: The general identification keywords usually have a type of "theme" and are refered to as "theme keywords". Other types and vocabularies are used for other information. Service Entry Resource Format (SERF) requires a Science and a Service GCMD Keyword. This concept is called "Subject" in the CSW Specification. | DIF (1) /dif:DIF/dif:Parameters/dif:Category DIF (1) /dif:DIF/dif:Parameters/dif:Topic DIF (1) /dif:DIF/dif:Parameters/dif:Term DIF (1) /dif:DIF/dif:Parameters/dif:Variable_Level_1 DIF (1) /dif:DIF/dif:Parameters/dif:Variable_Level_2 DIF (1) /dif:DIF/dif:Parameters/dif:Variable_Level_3 DIF (1) /dif:DIF/dif:Parameters/dif:Detailed_Variable ECHO (1) /*/echo:ScienceKeywords/echo:ScienceKeyword/echo:CategoryKeyword ECHO (1) /*/echo:ScienceKeywords/echo:ScienceKeyword/echo:TopicKeyword ECHO (1) /*/echo:ScienceKeywords/echo:ScienceKeyword/echo:TermKeyword ECHO (1) /*/echo:ScienceKeywords/echo:ScienceKeyword/echo:VariableLevel1Keyword/echo:Value ECHO (1) /*/echo:ScienceKeywords/echo:ScienceKeyword/echo:VariableLevel2Keyword/echo:Value ECHO (1) /*/echo:ScienceKeywords/echo:ScienceKeyword/echo:VariableLevel3Keyword ECHO (1) /*/echo:ScienceKeywords/echo:ScienceKeyword/echo:DetailedVariableKeyword ECS (1) /*/ecs:DisciplineTopicParameters/ecs:DisciplineKeyword ECS (1) /*/ecs:DisciplineTopicParameters/ecs:TopicKeyword ECS (1) /*/ecs:DisciplineTopicParameters/ecs:TermKeyword ECS (1) /*/ecs:DisciplineTopicParameters/ecs:VariableKeyword DCAT dct:keyword FGDC (1) /fgdc:metadata/fgdc:idinfo/fgdc:keywords/fgdc:theme/fgdc:themekey ISO (1) /*/gmd:identificationInfo/*/gmd:descriptiveKeywords/gmd:MD_Keywords[gmd:type/gmd:MD_KeywordTypeCode='theme']/gmd:keyword/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:descriptiveKeywords/mri:MD_Keywords[mri:type/mri:MD_KeywordTypeCode='theme']/mri:keyword/gco:CharacterString |
| Topic Category | High level category enumeration used in ISO | DIF (1) /dif:DIF/dif:ISO_Topic_Category DCAT dct:category ISO (1) /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:topicCategory/gmd:MD_TopicCategoryCode ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:topicCategory/mri:MD_TopicCategoryCode |
| Distribution Contact | Contact information for the organization or individual that distributes the resource. | DIF /dif:DIF/dif:Data_Center/dif:Personnel/dif:Role ECHO /*/echo:ArchiveCenter ECS /*/ecs:ArchiveCenter DCAT dct:contactPoint FGDC /fgdc:metadata/fgdc:distinfo/fgdc:distrib/fgdc:cntinfo ISO /gmd:MD_Metadata/gmd:distributionInfo/gmd:MD_Distribution/gmd:distributor/gmd:MD_Distributor/gmd:distributorContact/gmd:CI_ResponsibleParty ISO-1 /mdb:MD_Metadata/mdb:distributionInfo/mrd:MD_Distribution/mrd:distributor/mrd:MD_Distributor/mrd:distributorContact/cit:CI_Responsibility |
| Abstract | A paragraph describing the resource. Note: This concept is called "Desciption" in Catalog Services for the Web. | DIF /dif:DIF/dif:Summary/dif:Abstract ECHO /*/echo:Description ECS /*/ecs:CollectionDescription DCAT dct:description FGDC /fgdc:metadata/fgdc:idinfo/fgdc:descript/fgdc:abstract ISO /*/gmd:identificationInfo/*/gmd:abstract/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:abstract/gco:CharacterString |
| Metadata Standard Citation | The name of the standard to which the metadata conforms | DIF /serf:DIF/serf:Metadata_Name FGDC /fgdc:metadata/fgdc:metainfo/fgdc:metstdn ISO /gmd:MD_Metadata/gmd:metadataStandardName ISO-1 /mdb:MD_Metadata/mdb:metadataStandard |
| Metadata Standard Version | The name of the standard to which the metadata conforms | DIF /serf:DIF/serf:Metadata_Version FGDC /fgdc:metadata/fgdc:metainfo/fgdc:metstdv ISO /gmd:MD_Metadata/gmd:metadataStandardVersion ISO-1 /mdb:MD_Metadata/mdb:metadataStandard/cit:CI_Citation/cit:identifier/mcc:MD_Identifier/mcc:version |
DIF for Data Discovery-Highly Recommended
The Directory Interchange Format (DIF) is a NASA metadata format used to create directory entries that describe scientific data sets. The attributes in the spiral below are highly recommended by the DIF standard. Additonal documentation is available via the following online references:
Source: Interactive Write a DIF Guide DIF standard specification
| Concept | Description | Dialect (Fit) Paths |
|---|---|---|
| Complete Citation | Complete citation for the resource as a text blob. | ECHO /*/echo:CitationForExternalPublication ECS /*/ecs:CitationforExternalPublication |
| Resource Contact | The organization or person responsible for answering questions about the resource. | ISO /*/gmd:identificationInfo/*/gmd:pointOfContactPro ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:pointOfContact/cit:CI_Responsibility[cit:role/cit:CI_RoleCode='pointOfContact'] ECHO /*/echo:Contacts/echo:Contact DIF /dif:DIF/dif:Personnel[dif:Role='INVESTIGATOR'] ECS /CollectionMetaDataFile/CollectionMetaDataSets/Collections/CollectionMetaData/Contact[Role='User Services'] DCAT dct:person |
| Online Resource | Online Resource for the cited resource | ISO //gmd:CI_Citation/gmd:citedResponsibleParty/gmd:CI_ResponsibleParty/gmd:contactInfo/gmd:CI_Contact/gmd:onlineResource/gmd:CI_OnlineResource ISO-1 //cit:CI_Citation/cit:onlineResource/cit:CI_OnlineResource DIF /dif:DIF/dif:Data_Set_Citation/dif:Online_Resource DIF /dif:DIF/dif:Reference/dif:Online_Resource |
| Instrument | Information about the instrument used to make the observations. | ISO /gmi:MI_Metadata/gmi:acquisitionInformation/gmi:MI_AcquisitionInformation/gmi:instrument/gmi:MI_Instrument ISO /gmi:MI_Metadata/gmi:acquisitionInformation/gmi:MI_AcquisitionInformation/gmi:platform/gmi:MI_Platform/gmi:instrument/gmi:MI_Instrument ISO-1 /mai:MI_Metadata/mai:acquisitionInformation/mac:MI_AcquisitionInformation/mac:instrument/mac:MI_Instrument ISO-1 /mai:MI_Metadata/mai:acquisitionInformation/mac:MI_AcquisitionInformation/mac:platform/mac:MI_Platform/mac:instrument/mac:MI_Instrument ECHO //echo:Platforms/echo:Platform/echo:Instruments/echo:Instrument DIF /dif:DIF/dif:Sensor_Name |
| Platform | The platform used to collect the observations. | ISO /gmi:MI_Metadata/gmi:acquisitionInformation/gmi:MI_AcquisitionInformation/gmi:platform/gmi:MI_Platform ISO-1 /mai:MI_Metadata/mai:acquisitionInformation/mac:MI_AcquisitionInformation/mac:platform/mac:MI_Platform ECHO /*/echo:Platforms/echo:Platform DIF /dif:DIF/dif:Source_Name |
| Temporal Extent | The temporal extent of the resource | ISO /*/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:temporalElement/gmd:EX_TemporalExtent ISO-1 /*/mri:MD_DataIdentification/mri:extent/gex:EX_Extent/gex:temporalElement/gex:EX_TemporalExtent ECHO /*/Temporal/RangeDateTime FGDC /fgdc:metadata/fgdc:idinfo/fgdc:timeperd/fgdc:timeinfo/fgdc:rngdates |
| Paleo-Temporal Coverage | For paleoclimate or geologic data, “Paleo_Temporal_Coverage†is the period of time covered by the data collected. | DIF /dif:DIF/dif:Paleo_Temporal_Coverage |
| Bounding Box | A bounding box for identifying a geographic area of interest Note: This concept is called "Coverage" in the CSW Specification | ISO /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicBoundingBox ISO /*/gmd:identificationInfo/srv:SV_ServiceIdentification/srv:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicBoundingBox ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:extent/gex:EX_Extent/gex:geographicElement/gex:EX_GeographicBoundingBox ECHO /*/echo:Spatial/echo:HorizontalSpatialDomain/echo:Geometry/echo:BoundingRectangle DIF /dif:DIF/dif:Spatial_Coverage FGDC /fgdc:metadata/fgdc:idinfo/fgdc:spdom/fgdc:bounding |
| Place Keyword | A comma separated list of key words and phrases that give the location of the resource. Note: Some dialects include keywords, but they do not include mechanisms for identifying the type. In those cases it is difficult to unambiguously identify place keywords. | ISO /*/gmd:identificationInfo/*/gmd:descriptiveKeywords/gmd:MD_Keywords[gmd:type/gmd:MD_KeywordTypeCode='place']/gmd:keyword/gco:CharacterString ISO /gmd:MD_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicDescription/gmd:geographicIdentifier/gmd:MD_Identifier/gmd:code/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:descriptiveKeywords/mri:MD_Keywords[mri:type/mri:MD_KeywordTypeCode='place']/mri:keyword/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:extent/gex:EX_Extent/gex:geographicElement/gex:EX_GeographicDescription/gex:geographicIdentifier/mcc:MD_Identifier/mcc:code/gco:CharacterString DIF /dif:DIF/dif:Location/dif:Location_Category DIF /dif:DIF/dif:Location/dif:Location_Type DIF /dif:DIF/dif:Location/dif:Location_Subregion1 DIF /dif:DIF/dif:Location/dif:Location_Subregion2 DIF /dif:DIF/dif:Location/dif:Location_Subregion3 DIF /dif:DIF/dif:Location/dif:Detailed_Location FGDC /fgdc:metadata/fgdc:idinfo/fgdc:keywords/fgdc:place/fgdc:placekey |
| Spatial Resolution | The nominal scale and/or spatial resolution of the resource. | ISO /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:spatialResolution ISO-1 /*/mdb:identificationInfo/*/mri:spatialResolution |
| Temporal Resolution | The smallest time step included in the resource. | ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:temporalResolution/gts:TM_PeriodDuration |
| Resource Title | A short description of the resource. The title should be descriptive enough so that when a user is presented with a list of titles the general content of the data set can be determined. | ISO /*/gmd:identificationInfo/*/gmd:citation/gmd:CI_Citation/gmd:title/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:citation/cit:CI_Citation/cit:title/gco:CharacterString ECHO /*/echo:ShortName>/*/echo:LongName DIF /dif:DIF/dif:Entry_Title DIF /dif:DIF/dif:Data_Set_Citation/dif:Dataset_Title ECS /*/ecs:ShortName > /*/ecs:LongName FGDC /fgdc:metadata/fgdc:idinfo/fgdc:citation/fgdc:citeinfo/fgdc:title DCAT dct:title |
| Quality Statement | Information about the quality of the data or any quality assurance procedures followed in producing the data. | DIF /dif:DIF/dif:Quality |
| Resource Access Constraints | Information about any constraints for accessing the data set. This includes any special restrictions, legal prerequisites, limitations and/or warnings on obtaining the data set. Some words that may be used in this field include: Public, In-house, Limited, Additional detailed instructions on how to access the data can be entered in this field. | ISO /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:resourceConstraints/gmd:MD_LegalConstraints/gmd:legalConstraints/gmd:MD_RestrictionCode ISO /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:resourceConstraints/gmd:MD_LegalConstraints/gmd:otherConstraints/gco:CharacterString ISO /*/gmd:identificationInfo/srv:SV_ServiceIdentification/srv:restrictions/gmd:MD_LegalConstraints/gmd:legalConstraints/gco:CharacterString ISO /*/gmd:identificationInfo/srv:SV_ServiceIdentification/srv:restrictions/gmd:MD_LegalConstraints/gmd:otherConstraints/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:resourceConstraints/mco:MD_Constraints ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:resourceConstraints/mco:MD_LegalConstraints ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:resourceConstraints/mco:MD_SecurityConstraints ECHO /*/echo:RestrictionFlag ECHO /*/echo:RestrictionComment ECHO /*/echo:Visible DIF /dif:DIF/dif:Access_Constraints ECS /*/ecs:AccessConstraints FGDC /fgdc:metadata/fgdc:idinfo/fgdc:accconst |
| Resource Use Constraints | Information about how the data may or may not be used after access is granted to assure the protection of privacy or intellectual property. This includes any special restrictions, legal prerequisites, terms and conditions, and/or limitations on using the data set. Data providers may request acknowledgement of the data from users and claim no responsibility for quality and completeness of data. | ISO /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:resourceConstraints/gmd:MD_Constraints/gmd:useLimitation/gco:CharacterString ISO /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:resourceConstraints/gmd:MD_LegalConstraints/gmd:useConstraints/gmd:MD_RestrictionCode ISO /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:resourceConstraints/gmd:MD_LegalConstraints/gmd:otherConstraints/gco:CharacterString ISO /*/gmd:identificationInfo/srv:SV_ServiceIdentification/srv:restrictions/gmd:MD_LegalConstraints/gmd:legalConstraints/gco:CharacterString ISO /*/gmd:identificationInfo/srv:SV_ServiceIdentification/srv:restrictions/gmd:MD_LegalConstraints/gmd:otherConstraints/gco:CharacterString ISO /*/gmd:identificationInfo/srv:SV_ServiceIdentification/srv:restrictions/gmd:MD_Constraints/gmd:useLimitation/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:resourceConstraints/mco:MD_Constraints ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:resourceConstraints/mco:MD_LegalConstraints ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:resourceConstraints/mco:MD_SecurityConstraints ECHO /*/echo:RestrictionFlag ECHO /*/echo:RestrictionComment DIF /dif:DIF/dif:Use_Constraints FGDC /fgdc:metadata/fgdc:idinfo/fgdc:useconst |
| Media | Media on which the resource is available | ISO /gmd:MD_Metadata/gmd:distributionInfo/gmd:MD_Distribution/gmd:transferOptions/gmd:MD_DigitalTransferOptions/gmd:offLine/gmd:MD_Medium/gmd:name/gmd:MD_MediumNameCode/@codeListValue ISO-1 /mdb:MD_Metadata/mdb:distributionInfo/mrd:MD_Distribution/mrd:transferOptions/mrd:MD_DigitalTransferOptions/mrd:offLine/mrd:MD_Medium/mrd:name/cit:CI_Citation/cit:title/gco:CharacterString DIF /dif:DIF/dif:Distribution/dif:Distribution_Media FGDC /fgdc:metadata/fgdc:dataqual/fgdc:lineage/fgdc:sinfo/fgdc:type |
| Transfer Size | The size of the digital resource | ISO /gmd:MD_Metadata/gmd:distributionInfo/gmd:MD_Distribution/gmd:distributionFormat/gmd:MD_Format/gmd:formatDistributor/gmd:MD_Distributor/gmd:distributorTransferOptions/gmd:MD_DigitalTransferOptions/gmd:transferSize/gco:Real ISO /gmd:MD_Metadata/gmd:distributionInfo/gmd:MD_Distribution/gmd:distributor/gmd:MD_Distributor/gmd:distributorTransferOptions/gmd:MD_DigitalTransferOptions/gmd:transferSize/gco:Real ISO-1 /mdb:MD_Metadata/mdb:distributionInfo/mrd:MD_Distribution/mrd:distributionFormat/mrd:MD_Format/mrd:formatDistributor/mrd:MD_Distributor/mrd:distributorTransferOptions/mrd:MD_DigitalTransferOptions/mrd:transferSize/gco:Real ISO-1 /mdb:MD_Metadata/mdb:distributionInfo/mrd:MD_Distribution/mrd:distributor/mrd:MD_Distributor/mrd:distributorTransferOptions/mrd:MD_DigitalTransferOptions/mrd:transferSize/gco:Real ECHO /echo:Granule/echo:DataGranule/echo:SizeMBDataGranule DIF /dif:DIF/dif:Distribution/dif:Distribution_Size |
| Resource Format | The physical or digital manifestation of the resource | ISO /*/gmd:distributionInfo/gmd:MD_Distribution/gmd:distributor/gmd:MD_Distributor/gmd:distributorFormat/gmd:MD_Format/gmd:name/gco:CharacterString ISO /*/gmd:distributionInfo/gmd:MD_Distribution/gmd:distributionFormat/gmd:MD_Format/gmd:name/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:distributionInfo/mrd:MD_Distribution/mrd:distributionFormat/mrd:MD_Format ISO-1 /mdb:MD_Metadata/mdb:distributionInfo/mrd:MD_Distribution/mrd:distributor/mrd:MD_Distributor/mrd:distributorFormat/mrd:MD_Format ECHO /*/echo:DataFormat DIF /dif:DIF/dif:Distribution/dif:Distribution_Format |
| Resource Language | The language of the resource. | ISO /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:language/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:defaultLocale/lan:PT_Locale/lan:language/lan:LanguageCode ISO-1 /mdb:MD_Metadata/mdb:otherLocale/lan:PT_Locale/lan:language/lan:LanguageCode DIF /dif:DIF/dif:Data_Set_Language |
| Resource Status | The status of the resource | ISO /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:status/gmd:MD_ProgressCode ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:status/mcc:MD_ProgressCode DIF /dif:DIF/dif:Data_Set_Progress FGDC /fgdc:metadata/fgdc:idinfo/fgdc:status |
xPath Note: The xPaths included in this table use several wildcards. // means any path, so //gmd:CI_ResponsibleParty indicates a gmd:CI_ResponsibleParty anywhere in an XML file. /*/ indicates a single level with several possible elements. This usually indicates one of several concrete realizations of an abstract object. For example /*/gmd:identificationInfo could be gmd:MD_Metadata/gmd:identificationInfo or gmi:MI_Metadata/gmd:identificationInfo and gmd:identificationInfo//*/gmd:descriptiveKeywords could be gmd:identificationInfo/gmd:MD_DataIdentification/gmd:descriptiveKeywords or gmd:identificationInfo/srv:SV_ServiceIdentification/gmd:descriptiveKeywords. Fit: The fit of the dialect path with the concept is estimated on a scale of 1 = excellent two-way fit, 2 = one-way fit or some other problem, 3 - extension required.
