ISO Building Blocks in the CMR

Interim Collection Comparison Report for Big Earth Data Initiative

Metadata Source: CMR Metadata Collections

Metadata Dialect: ISO 19115-2

Evaluation Target: UMM-Collection metadata profile

The Unified Metadata Model Collection (UMM-Collection) profile describes documentation concepts that are considered important for collection level metadata. The profile is includes three documentation levels (Required, Recommended and Optional).

Metadata Collection

Alaska Satellite Facility (ASF)
Crustal Dynamics Data Information System (CDDIS)
Global Hydrology Resource Center (GHRC)
Goddard Earth Sciences Data and Information Center (GES_DISC)
Level 1 and Atmosphere Archive and Distribution System (LAADS)
Land, Atmosphere Near real-time Capability for EOS (LANCEMODIS)
Land, Atmosphere Near real-time Capability for EOS (LANCEAMSR2)
Langley Research Center (LARC)
Langley Research Center (LARC_ASDC) Atmospheric Science Data Center
Land Process DAAC - EOS Core System (LPDAAC_ECS)
National Snow and Ice Data Center Version 0 (NSIDCV0)
National Snow and Ice Data Center EOS Core System (NSIDC_ECS)
Ocean Biology Processing Group (OBPG)

Oak Ridge National Laboratory (ORNL)
Physical Oceanography DAAC (PODAAC)
Socioeconomic Data and Applications Center (SEDAC)
U.S. Geological Survey Earth Resources Observation Systems (USGS_EROS)
(AU_AADC)
ESA
EUMETSAT
ISRO
JAXA
LM_FIRMS
NOAA_NCEI
USGS_LTA

Overview

We examined over 15,000 metadata records from 26 collections extracted from the Common Metadata Repository (CMR) during April 2017. The links below connect to tables in google sheets which provide the average number of occurrences of UMM-Collection elements in each of these collections. A value of 1 or more typically (although not necessarily) indicates that the element is included one or more times in each record in a collection. A value < 1.0 is typically the percentage of records in a collection that include the metadata element. Cells with pink backgrounds indicate values of 0, meaning the element is completely missing from the collection.

Where are contacts documented in the CMR?

The table below shows how CMR metadata collections document contact information. The following contact types are considered: 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 Metadata Contact organization exists in all CMR metadata collections and is complete in 22/26 collections
The Point Of Contact organization exists in all CMR metadata collections and is complete is all collections with the exception of OMINRT
Resource Contact information is missing from the majority of CMR metadata collections and is complete in 0 CMR collections
Distributor Contact information is included in 20/26 of CMR metadata collections and is complete in 12 CMR collections
Processor Contact information is included in 10 NASA metadata collections and is complete in 3 NASA collections

Where are Identifiers used in CMR metadata?

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.

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

Resource Identifier and File Identifier elements are complete in all CMR metadata collections
Platform identifier exists in all CMR metadata collections and is complete in 22/26
Instrument Identifier exists in all CMR metadata collections and is complete in 15/26 collections
Reference System identifier exists in 25/26 CMR collections and is complete in 15/26 collections
Operation identifiers exists in 22/26 CMR collections and is complete in 9/26 collections
Sensor identifiers exists in 14 NASA metadata collections and is complete in 3 NASA collections
Geographic Identifier exists in 7 NASA metadata collections and is complete in 1 NASA collection
Aggregate Dataset Name Identifier exists in 9 CMR metadata collections and is complete in 0 CMR collections

Where are Citations used in CMR metadata?

The table below shows where Citations are used in CMR metadata collections.

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

Resource Citation date and title elements are complete in all CMR collections
Instrument Citation exists in all CMR metadata collection and is complete in 15/26 CMR collections
Contact Information for the Resource Citation is included in 3/26 CMR metadata collections and is complete in 0 CMR collections

Where are External Links (OnlineResources) used in CMR metadata?

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

An Online Resource URL for Distributor Transfer Options exists in all CMR metadata collections with the exception of OMINRT and is complete in 21 CMR collections
An Online Resource URL for Keyword Thesaurus exists in 15/26 CMR metadata collections and is complete in 8 CMR collections
An Online Resource URL for the Metadata Contact and Point Of Contact exists in 17/26 CMR metadata collections and are complete in 2 or less CMR collections
An Online Resource URL for Associated Resources exists in 7/26 CMR metadata collections and is complete in 0 CMR collections
An Online Resource URL for Distributor Contact exists in 11/26 CMR metadata collections and is complete in 0 CMR collections
An Online Resource URL for Processor Contact exists in 2 NASA metadata collections and is complete in 0 CMR collections
An Online Resource description for Point Of Contact exists in 1 NASA metadata collections and is complete in 0 CMR collections

Where are Geographic Extent elements used in CMR metadata?

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

Bounding Box extent elements are used in all CMR metadata collection with the exception of OMINRT and are complete in 11/26 CMR collections
18 out of 26 CMR collection are using the extentTypeCode element with a value of '1'. This field is complete in 6/26 CMR
8 NASA collections are using the gmd:geographicIdentifier/gmd:description. Commonly recurring values include:

- 'HORIZONTALTILENUMBER - Horizontal tile number of a grid, which increases from left to right'
- 'VERTICALTILENUMBER - Vertical tile number of a grid, which increases from top to bottom'
- 'TileID - MODIS Land tile identification number which represents a geographical area on the surface of the Earth bounded by latitude and longitude coordinates'
- 'Universal Transverse Mercator (UTM)ZoneIdentifier'
7 NASA collections include a Geographic Identifier code with the most common value 'Universal Transverse Mercator (UTM)'

Where are Temporal Extent elements used in CMR metadata?

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

TimePeriod/beginPosition exists in all CMR collections and is complete in 22 CMR collections
TimePeriod/end Position exists in 24/28 CMR collections and is complete in 2 CMR collections
TimePeriod/endPosition exists in 7 CMR collections with an attribute value of indeterminatePosition='Now'. This element is complete in 2 NASA collections.
TimeInstant/timePosition exists in 1 CMR collection with an attribute value of framevalue='Eastern-Daylight'.

Where are Date elements used in CMR metadata?

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

Metadata Creation/Modified Date (timeStamp element) is complete in all CMR metadata collections
Resource Citation Date is complete in all CMR collections
Keyword Thesauraus Name Date exists in 15 NASA collections and is complete in 7 NASA collections
AggregateDataSetName Date exists in 7 CMR metadata collections