Metadata Elements

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DMF metadata elements

General

Viewpoints

The DGIWG Metadata Vision defines a general metadata use case involving metadata elements in four different contexts (i.e. use case scenarios):

  • Discovery concerns the most important metadata elements, i.e. the metadata elements involved when a user needs to discover existing resources;
  • Evaluation concerns the metadata elements needed to understand whether the discovered resources meet the user requirements;
  • Use concerns the metadata elements needed to access and use the resource;
  • Management concerns the metadata elements needed to manage the existing resources.
From a user viewpoint, the involved DMF metadata elements depend on these four contexts. Four viewpoints corresponding each to one of these four contexts are expressed here as sets of metadata elements applicable to the specific context.#
A candidate Metadata Catalogue shall take into account the DMF metadata element viewpoints in the interactions with the users (user interface, sets of metadata elements provided to the users in a given context).


Metadata element sets

The DMF metadata elements document different aspects of the resources including their identification, the related quality information, the spatial representation and the content description of the resource data. Each aspect is dealt with by the definition of an identified element set grouping the metadata elements covering the documentation of the aspect.

This grouping mechanism is important for the users especially when the number of metadata elements to be considered becomes high.#
A candidate Metadata Catalogue shall take into account the DMF metadata element sets in the interactions with the users.


Metadata classes

The DGIWG Metadata Foundation defines several metadata classes:
*
DMF/Core defines the minimum set of metadata elements to be implemented by any metadata catalogue. This set satisfies the discovery use case.
  • DMF/Common is an additional set of metadata elements for a more complete description of any type of resource supported by DMF. It extends DMF/Core and covers discovery and basic evaluation use cases.
  • DMF/Services extends DMF/Core for service metadata and can be used together with DMF/Common (i.e. it is possible to use DMF/Services on top of DMF/Core (if DMF/Common elements are not needed) or on top of DMF/Common for an extensive profile).
  • DMF/Data extends DMF/Common for data related resources (i.e. dataset, series and tile). DMF/Data adds metadata elements for evaluation and use.
  • DMF/Data+ extends DMF/Data for the implementation of coverage quality results and other metadata elements introduced in ISO 19115-2 but having some applications for any geospatial product.
  • A DMF/Sensor class extending DMF/Data for sensors.
  • DMF/Defence extends DMF/Core or DMF/Common for military oriented needs including NATO needs (extensions defined in NGMP, particularly security). It is needed to handle metadata to be exchanged with NATO in conformance with NGMP. DMF/Defence can be implemented with DMF/Core and possibly any other metadata class.
  • DMF/Specific is an extension of the ISO metadata standards for high level military implementation of the DMF metadata elements.
  1. The documentation of a candidate Metadata Catalogue shall list the supported DMF metadata classes as defined in clause 5.1.3of this document.
  2. A candidate Metadata Catalogue shall support at least the DMF/Core.
  3. A candidate Metadata Catalogue having an output facility shall propose a mechanism to output a DMF Metadata Set conforming to one of the supported DMF metadata classes.
  4. A candidate profile of the DMF shall define the profiled DMF metadata classes. It shall respect the rules for profiling a DMF metadata class defined in Annex A.
  5. A candidate profile of the DMF can define one or more metadata class extending the DMF. It shall respect the rules for extending DMF defined in Annex A.


Metadata element requirements

Each DMF metadata element pertains to one metadata class. Each metadata element of the DMF has:*
A unique Identifier introduced for consistency of the documentation;
  • A Title serving as a human-oriented comprehensive identifier;
  • An indication of the related metadata class;
  • A Description statement which may include the expression of constraints (preceded by “Constraints:”) applicable to the metadata element;
  • A Value Domain defining the applicable data types and vocabularies, as well as the applicable restrictions of the domain of values. Individual values are expressed in bold.
  • A Cardinality statement.


Each basic type and vocabulary also pertains to one metadata class. Some data types are complex, i.e. they comprise of a set of properties also having an identifier, a title, a description, an indication of the related metadata class, a value domain and a cardinality. A complex data type implicitly pertains to the metadata classes defined for its properties (i.e. the complex type properties may relate to different metadata classes).

The cardinality statement may be expressed as:* a number of occurrences (typically 1 indicates that one and only one occurrence is expected), or;

  • a range expressing a minimum and maximum number of occurrences. The format of a range of occurrences is nm where:
  • n is a positive integer or 0 indicating that the field is optional, i.e. it may not occur on any resource;
  • m is a positive integer or * indicating that the maximum is unbounded.


The cardinality statement defines the minimum and maximum number of occurrences of the DMF metadata elements in terms of relevance for the types of resources supported by DMF. A metadata element is optional (i.e., its minimum occurrence is set to 0) when it may not occur when documenting any resource in the scope of DMF. Constraints are expressed when the relevance of the metadata elements is specific to some resource types or depends on the value of other metadata elements.#
Within a DMF Metadata Set describing a dataset, dataset series, service, tile, or nonGeographicDataset, each metadata element of the supported metadata classes shall occur as many times as specified by the cardinality and constraint statements.
  1. Within a DMF Metadata Set describing a dataset, dataset series, service, tile, or nonGeographicDataset, each instance of a property or metadata element having a complex data type shall comprise the property instances applicable to the supported metadata classes according to the data type definition.
  2. The content of each occurrence of a DMF Metadata Set shall conform to the value domain (including the data type definition) and description (including the identified constraints) of the metadata element.
  3. A candidate Metadata Catalogue shall be able to manage each of the metadata elements, data types and complex data type properties pertaining to the supported metadata classes, whether it is optional or not.


Reciprocally, a mandatory metadata element (i.e., its minimum occurrence is set to 1 or more) does not have to be implemented by a metadata catalogue if it is not part of the supported metadata classes.
#
A candidate Metadata Catalogue shall at least be able to ingest and/or output DMF Conformant Metadata Sets, depending on the user requirements.


The constraints applicable to DMF profiles with respect to the cardinality of the metadata elements are part of the rules for profiling defined in Annex A.

The following documentation of the DMF metadata elements is composed of:* The overview of the DMF metadata elements (see clause 5.2) which expresses the identifier, the title, the metadata class and the cardinality statement of the DMF Metadata Elements. It also organizes the metadata elements into four different viewpoints

  • The detailed description of the DMF metadata elements organised by metadata element sets (see clause Error: Reference source not found).


Metadata Element Overview

For a detailed description of the metadata elements see clause 5.3.


Identifier Title Card Metadata Class align=center style="border:0.75pt solid #000000;padding:0.132cm;" | Viewpoints
D E U M
MDSID Metadata Set Identifier 0..1 DMF/Core X
MDLINK Metadata Linkage 0..1 DMF/Specific X
MDPTMD Parent Metadata Set 0..1 DMF/Common X
MDDLOC Metadata Default Locale 1 DMF/Core X X X
MDTLOC Metadata Translation 0..* DMF/Common X X
MDRPTY Metadata Responsible Party 1..* DMF/Core X X X X
MDDATE Metadata Date Stamp 1 DMF/Core X X X X
MDSTD Metadata Standard 1 DMF/Core X X X
MDSCST Metadata Security Constraint 0..* DMF/Common X X X X
MDREL Metadata Releasability Addressee 0..* DMF/Defence X X X X
MDLCST Metadata Legal Constraint 0..* DMF/Common X X X
MDMFRQ Metadata Maintenance Frequency 0..1 DMF/Common X X X
RSTITLE Resource Title 1 DMF/Core X X X X
RSALT Resource Alternate Title 0..1 DMF/Common X X X
RSABSTR Resource Abstract 1 DMF/Core X X X X
RSPURP Resource Purpose 0..1 DMF/Core X X X X
RSTYPE Resource Type Code 1 DMF/Core X X X X
RSTYPN Resource Type Name 0..1 DMF/Core X X X X
RSED Resource Edition 0..1 DMF/Core X X X
RSEDDAT Resource Edition Date 0..1 DMF/Core X X X
RSID Resource Identifier 0..* DMF/Core X X X X
RSKWDS Resource Keyword Set 0..* DMF/Core X X X X
THUMB Resource Thumbnail 0..1 DMF/Core X X X X
GPHICS Resource Graphics 0..* DMF/Common X X X
RSSRES Resource Spatial Resolution 0..* DMF/Core X X X X
RSTRES Resource Temporal Resolution 0..* DMF/Common X X X
RSRPTP Resource Spatial Representation Type 0..1 DMF/Core X X X X
RSTOPIC Resource Topic Category 0..* DMF/Core X X X X
RSDLOC Resource Default Locale 1 DMF/Core X X X
RSTLOC Resource Other Locale 0..* DMF/Core X X X
DGITYP Geospatial Information Type 0..1 DMF/Core X X X X
RSGFLV Resource Georeferencing Level 0..1 DMF/Core X X X X
RSPREF Resource Representation Form 0..1 DMF/Core X X X X
RSDTLVL Resource Data Level 0..1 DMF/Defence X X X X
RSTHEME Resource Theme 0..* DMF/Core X X X X
RSSERI Name of Resource Series 0..1 DMF/Core X X X X
RSSHNA Resource Sheet Name 0..1 DMF/Core X X X X
RSENVD Resource Environment Description 0..1 DMF/Data X X
RSREM Resource Remark 0..1 DMF/Common X X X X
RSFMT Resource Format 0..1 DMF/Data X X X
SRTYPE Service Type 1 DMF/Services X X X X
SRTVER Service Type Version 1 DMF/Services X X X X
SRSTD Service Standard 0..1 DMF/Services X X X
SRCPLING Service Coupling Type 1 DMF/Services X X X
SROPRS Resource Operated by the Service 0..* DMF/Services X X X
SROPER Service Operation 1..* DMF/Services X X X
SRCORS Service Coupled Resource 0..* DMF/Services X X
RCGRSPREP Spatial Representation of a Georectified Gridded Coverage 0..1 DMF/Data X X
RFGRSPREP Spatial Representation of a Georeferenceable Gridded Coverage 0..1 DMF/Sensor X X
GRCINF Content Information of the Coverage 0..1 DMF/Data+ X X
ASSOC Image Association Type 0..1 DMF/Sensor X X X
SPECTMOD Spectral Mode 0..1 DMF/Sensor X X X
VCTOLVL Topology Level 0..1 DMF/Data X X
VGEOM Geometric Object 0..* DMF/Data X X
FCDESC Feature Catalogue Description 0..1 DMF/Data X X
RSEXT Resource Extent 0..* DMF/Core X X X X
RSRSYS Resource Reference System 0..* DMF/Core X X
RSSTAT Resource Status 0..1 DMF/Common X
RSDATE Resource Reference Date 1..* DMF/Core X X X X
RSRPTY Resource Responsible Party 0..* DMF/Core X X X
RSMTNC Resource Maintenance 0..1 DMF/Common X X X
RSSCST Resource Security Constraint 0..* DMF/Core X X X X
RSREL Resource Releasability 0..* DMF/Defence X X X X
RSUSE Resource Use Limitation 0..* DMF/Core X X X
RSLCST Resource Legal Constraint 0..* DMF/Core X X X
RSLING Resource Lineage 1 DMF/Core X X X X
RSRQR Resource Regulated Quality Report 0..* DMF/Common X X X
RSUQR Resource Unspecified Quality Report 0..* DMF/Common X X X
RSSRC Source of the Resource 0..* DMF/Common X X X
RSPRST Resource Process Step 0..* DMF/Common X X X
RSSPUS Resource Usage 0..* DMF/Common X X
RSDFMT Resource Distribution Format 1..* DMF/Core X X X X
RSONLLC Resource Online Location 0..* DMF/Core X X X
RSUD Resource Unit of Distribution 0..1 DMF/Data X X
RSTS Resource Transfer Size 0..1 DMF/Data X X
RSOFDM Resource Offline Distribution Medium 0..* DMF/Data X X
ACINS Acquisition Instrument 1..* DMF/Sensor X X X X
ACPLAT Acquisition Platform Information 0..1 DMF/Sensor X X X
ACMETCD Meteorological Conditions of Acquisition 0..1 DMF/Sensor X X
ACDATE Acquisition Date Time 0..1 DMF/Sensor X X X X
SUNAZ Sun Azimuth 0..1 DMF/Sensor X X X
SUNEL Sun Elevation 0..1 DMF/Sensor X X X