Data Discovery (DIF)
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.
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 SERF /serf:SERF/serf:Entry_ID |
| 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. | ADIwg /adiwg:project/adiwg:idinfo/adiwg:citation/adiwg:citeinfo/adiwg:title DIF /dif:DIF/dif:Entry_Title DIF /dif:DIF/dif:Data_Set_Citation/dif:Dataset_Title DCAT /dct:title Dryad dcterms:title ECHO /*/echo:ShortName>/*/echo:LongName ECS /*/ecs:ShortName > /*/ecs:LongName EML /eml:dataset/eml:title/eml:text FGDC /fgdc:metadata/fgdc:idinfo/fgdc:citation/fgdc:citeinfo/fgdc:title HDF5.1 /hdf5:HDF5-File/hdf5:RootGroup/hdf5:Attribute[@Name='title']/hdf5:Data/hdf5:DataFromFile HDF5.1 /hdf5:HDF5-File/hdf5:RootGroup/hdf5:Group[@Name='METADATA']/hdf5:Group[@Name='COLLECTIONMETADATA']/hdf5:Attribute[@Name='LongName']/hdf5:Data/hdf5:DataFromFile 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 UMM /umm:UMM/umm:CollectionCitation/umm:Title OGC-SOS /sos:Capabilities/ows:ServiceIdentification/ows:Title SERF /serf:SERF/serf:Entry_Title THREDDS /thredds:catalog/thredds:dataset/@name THREDDS /thredds:catalog/thredds:dataset/thredds:metadata/dc:title THREDDS //thredds:dataset[1]/@name netCDF /nc:netcdf/nc:attribute[@nc:name=title]/@nc:value |
| Theme 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. | ADIwg /adiwg:project/adiwg:idinfo/adiwg:keywords/adiwg:theme/adiwg:themekey 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 DCAT /dct:keyword Dryad dcterms:subject 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 EML (1) /eml:dataset/eml:keywordSet/eml:keyword/eml:text FGDC /fgdc:metadata/fgdc:idinfo/fgdc:keywords/fgdc:theme/fgdc:themekey HDF5.1 (1) /hdf5:HDF5-File/hdf5:RootGroup/hdf5:Attribute[@Name='keywords']/hdf5:Data/hdf5:DataFromFile HDF5.1 (1) /hdf5:HDF5-File/hdf5:RootGroup/hdf5:Group[@Name='METADATA']/hdf5:Group[@Name='COLLECTIONMETADATA']/hdf5:Group[@Name='DisciplineTopicParameters']/hdf5:Group/hdf5:Attribute[@Name='ECSDisciplineKeyword']/hdf5:Data/hdf5:DataFromFile HDF5.1 (1) /hdf5:HDF5-File/hdf5:RootGroup/hdf5:Group[@Name='METADATA']/hdf5:Group[@Name='COLLECTIONMETADATA']/hdf5:Group[@Name='DisciplineTopicParameters']/hdf5:Group/hdf5:Attribute[@Name='ECSTermKeyword']/hdf5:Data/hdf5:DataFromFile HDF5.1 (1) /hdf5:HDF5-File/hdf5:RootGroup/hdf5:Group[@Name='METADATA']/hdf5:Group[@Name='COLLECTIONMETADATA']/hdf5:Group[@Name='DisciplineTopicParameters']/hdf5:Group/hdf5:Attribute[@Name='ECSTopicKeyword']/hdf5:Data/hdf5:DataFromFile HDF5.1 (1) /hdf5:HDF5-File/hdf5:RootGroup/hdf5:Group[@Name='METADATA']/hdf5:Group[@Name='COLLECTIONMETADATA']/hdf5:Group[@Name='DisciplineTopicParameters']/hdf5:Group/hdf5:Attribute[@Name='ECSVariableKeyword']/hdf5:Data/hdf5:DataFromFile HDF5.1 (1) /hdf5:HDF5-File/hdf5:RootGroup/hdf5:Group[@Name='METADATA']/hdf5:Group[@Name='COLLECTIONMETADATA']/hdf5:Group[@Name='DisciplineTopicParameters']/hdf5:Group/hdf5:Group[@Name='ECSParameter']/hdf5:Attribute[@Name='ECSParameterKeyword']/hdf5:Data/hdf5:DataFromFile ISO (1) /*/gmd:identificationInfo/*/gmd:descriptiveKeywords/gmd:MD_Keywords[gmd:type/gmd:MD_KeywordTypeCode=[normalize-space()="theme"]]/gmd:keyword/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:descriptiveKeywords/mri:MD_Keywords[mri:type/mri:MD_KeywordTypeCode=[normalize-space()="theme"]]/mri:keyword/gco:CharacterString UMM (1) /umm:UMM/umm:ScienceKeywords/umm:Category UMM (1) /umm:UMM/umm:ScienceKeywords/umm:Topic UMM (1) /umm:UMM/umm:ScienceKeywords/umm:Term UMM (1) /umm:UMM/umm:ScienceKeywords/umm:VariableLevel1/umm:Value UMM (1) /umm:UMM/umm:ScienceKeywords/umm:VariableLevel1/umm:VariableLevel2/umm:Value UMM (1) /umm:UMM/umm:ScienceKeywords/umm:VariableLevel1/umm:VariableLevel2/umm:VariableLevel3/umm:Value UMM (1) /umm:UMM/umm:ScienceKeywords/umm:DetailedVariable OGC-SOS (1) /sos:Capabilities/ows:ServiceIdentification/ows:Keywords[ows:Type='theme']/ows:Keyword SERF /serf:SERF/serf:Keyword THREDDS (1) //thredds:metadata/thredds:keyword THREDDS (1) //thredds:dataset/thredds:keyword netCDF (1) /nc:netcdf/nc:attribute[@nc:name=keywords]/@nc:value |
| Topic Category | High level category enumeration used in ISO | DIF (1) /dif:DIF/dif:ISO_Topic_Category DCAT /dct:theme ISO (1) /*/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:topicCategory/gmd:MD_TopicCategoryCode ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:topicCategory/mri:MD_TopicCategoryCode UMM (1) /umm:UMM/umm:ISOTopicCategory SERF /serf:ISO_Topic_Category |
| Distribution Contact | Contact information for the organization or individual that distributes the resource. | DIF /dif:DIF/dif:Data_Center/dif:Personnel/dif:Role DCAT /dct:contactPoint ECHO /*/echo:ArchiveCenter ECS /*/ecs:ArchiveCenter FGDC /fgdc:metadata/fgdc:distinfo/fgdc:distrib/fgdc:cntinfo ISO /*/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 SERF /serf:SERF/serf:Service_Provider |
| Abstract | A paragraph describing the resource. Note: This concept is called "Desciption" in Catalog Services for the Web. | ADIwg /adiwg:project/adiwg:idinfo/adiwg:descript/adiwg:abstract DIF /dif:DIF/dif:Summary/dif:Abstract DCAT /dct:description Dryad dcterms:description ECHO /*/echo:Description ECS /*/ecs:CollectionDescription EML /eml:dataset/eml:abstract/eml:descendant FGDC /fgdc:metadata/fgdc:idinfo/fgdc:descript/fgdc:abstract HDF5.1 /hdf5:HDF5-File/hdf5:RootGroup/hdf5:Attribute[@Name='summary']/hdf5:Data/hdf5:DataFromFile HDF5.1 /hdf5:HDF5-File/hdf5:RootGroup/hdf5:Group[@Name='METADATA']/hdf5:Group[@Name='COLLECTIONMETADATA']/hdf5:Attribute[@Name='CollectionDescription']/hdf5:Data/hdf5:DataFromFile ISO /*/gmd:identificationInfo/*/gmd:abstract/gco:CharacterString ISO-1 /mdb:MD_Metadata/mdb:identificationInfo/*/mri:abstract/gco:CharacterString UMM /umm:UMM/umm:Summary OGC-SOS /sos:Capabilities/ows:ServiceIdentification/ows:Abstract SERF /serf:SERF/serf:Summary/serf:Abstract THREDDS //thredds:dataset/thredds:documentation[@type='abstract'] THREDDS //thredds:metadata/thredds:documentation[@type='abstract'] netCDF /nc:netcdf/nc:attribute[@nc:name='summary']/@nc:value |
| Metadata Standard Citation | The name of the standard to which the metadata conforms | DIF /dif:DIF/dif:Metadata_Name FGDC /fgdc:metadata/fgdc:metainfo/fgdc:metstdn ISO /*/gmd:metadataStandardName ISO-1 /mdb:MD_Metadata/mdb:metadataStandard SERF /serf:SERF/serf:Metadata_Name |
| Metadata Standard Version | The name of the standard to which the metadata conforms | DIF /dif:DIF/dif:Metadata_Version FGDC /fgdc:metadata/fgdc:metainfo/fgdc:metstdv ISO /*/gmd:metadataStandardVersion ISO-1 /mdb:MD_Metadata/mdb:metadataStandard/cit:CI_Citation/cit:identifier/mcc:MD_Identifier/mcc:version SERF /serf:SERF/serf:Metadata_Version |
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. 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. 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.
