Metadata Source: CMR Metadata Collections
Metadata Dialect: ISO 19115-2
Commonly used documentation objects (CUDOS) such as Citations, ReponsibleParty and OnlineResource are key building blocks in the ISO 19115 standard. These objects occur in many sections of the metadata model and are considered foundational to the standard. This page examines the usage of CUDOS in CMR metadata collections.
Metadata Collections
Overview
We examined over 15,000 metadata records from 26 NASA and IDN collections extracted from the Common Metadata Repository (CMR) during April 2017. The links below connect to Tables which present the results in two ways:
Tables that include "Exists" in their titles give the average number of times that the metadata items (elements or attributes) occur per metadata record.
Tables that include "Complete" in their titles give the % of records in a collection that include a metadata item. These values range from 0 (completely missing) to 1.0 (in all records) and do not provide information about how may times the item occurs.
Metadata serves an essential function in connecting users to people and organizations to help them access, use, and understand data. The ESDIS Common Metadata Repository (CMR) recognizes the importance of this type of information and includes two related elements in the Unified Metadata Model (UMM) Common Profile: Responsibility and Party. As elements in the Common Profile, these elements are included in all other UMM Profiles.
The Responsibility element broadly defines responsibilities related to data resources using the position of the element in the metadata model hierarchy. The UMM-Common Profile defines five responsibilities: Metadata Contact, Resource Author / Originator, Point of Contact, Distributor, and Processor. Each of these responsibilities can have multiple people or organizations (termed parties) associated with it. A RoleCode that is chosen from the standard ISO Codelist describes details of the roles of those parties. See Individuals, Organizations, and Roles for more information.
The Tables below shows how CMR metadata collections document contact information. Select the tabs at the top of the sheet to see results for: Metadata Contact, Point of Contact, Resource Contact, Distributor Contact and Processor.
Table 1:
Contact Information Exists in the CMR (Items, Elements and Attributes)
Contact Information Complete in the CMR (Items, Elements and Attributes)
Observations
The need for identifiers in metadata records was first recognized in the DIF Standard and FGDC Remote Sensing Extensions. These standards introduced identifiers for the metadata records. In ISO 19115 this role is addressed by the fileIdentifier, a character string included in the MD_ or MI_Metadata object. This character string has been replaced with an MD_Identifier in 19115-1.
Including fileIdentifiers in the ISO metadata records gives metadata creators a mechanism for uniquely identifying them. This is becoming more important as metadata records evolve from single files into collections of related objects that can be harvested into repositories like geo.data.gov along multiple paths. There is no reliable way to identify duplicate records without a unique identifier in the actual record.
If the metadata records belongs to a parent metadata collection the parentIdentifier field can be used to reference the parent collection.
Identifiers are also used to reference resources associated with the data set or service described by the metadata. For example platforms, instruments, software, documentation, reports, partners and products can all be unambiguously referenced and described with the MD_Identifier object.
The table below shows where Identifiers are used in CMR metadata collections. Identifiers enable specific metadata concepts such platforms, instruments, Sensors, etc to be unambiguously identified. See Identifiers for more information.
Table 2:
Identifier existence in the CMR (Elements)
Identifier existence in the CMR (Items: Elements and Attributes)
Identifier completeness in the CMR (Elements)
Identifier completeness in the CMR (Items: Elements and Attributes)
Observations
The table below shows where Citations are used in CMR metadata collections. See Citations for more information.
Table 3:
Citation existence in the CMR (Elements)
Citation existence in the CMR (Items: Elements and Attributes)
Citation completeness in the CMR (Elements)
Citation completeness in the CMR (Items: Elements and Attributes)
Observations
The table below shows where Online Resource elements are used in CMR metadata collections.
Table 4:
Online Resource existence in the CMR (Elements)
Online Resource existence in the CMR (Items: Elements and Attributes)
Online Resource completeness in the CMR (Elements)
Online Resource completeness in the CMR (Items: Elements and Attributes)
Observations
The table below shows where geographic elements are used in CMR metadata collections.
Table 5:
Geographic Extent existence in the CMR (Elements)
Geographic Extent existence in the CMR (Items: Elements and Attributes)
Geographic Extent completeness in the CMR (Elements)
Geographic Extent completeness in the CMR (Items: Elements and Attributes)
Observations
The table below shows where temporal elements are used in CMR metadata collections.
Table 6:
Temporal Extent existence in the CMR (Elements)
Temporal Extent existence in the CMR (Items: Elements and Attributes)
Temporal Extent completeness in the CMR (Elements)
Temporal Extent completeness in the CMR (Items: Elements and Attributes)
Observations
The table below shows the usage of Date elements are used in CMR metadata collections.
Table 7:
Date existence in the CMR (Elements)
Date existence in the CMR (Items: Elements and Attributes)
Date completeness in the CMR (Elements)
Date completeness in the CMR (Items: Elements and Attributes)
Observations
The table below shows the usage of keyword elements are used in CMR metadata collections.
Table 8:
Keyword existence in the CMR (Elements)
Keyword existence in the CMR (Elements and Attributes)
Keyword completeness in the CMR (Elements)
Keyword completeness in the CMR (Elements and Attributes)
Observations
The table below shows the usage of Description elements in CMR metadata collections. The Description field is commonly used
Table 8:
Description existence in the CMR (Elements)
Description existence in the CMR (Elements and Attributes)
Description completeness in the CMR (Elements)
Description completenss in the CMR (Elements and Attributes)
Observations