Unified Metadata Model (UMM): Introduction to UMM-C and UMM-G
The Unified Metadata Model (UMM) is used as a bridge to map between each of the CMR-supported metadata standards. Within EOSDIS, a number of different objects require descriptive metadata that is modeled using a corresponding UMM profile. For example, collection and granule objects are modeled using the UMM-C and UMM-G profiles, respectively. While UMM-C and UMM-G are separate entities, some elements are common to each profile and are therefore modeled using UMM-Common. In this section, we break down the main differences between UMM-C and UMM-G and discuss the overlapping UMM-Common elements.
UMM-Common: Elements Common between Collections and Granules
The table below illustrates which elements in UMM-Common are shared between both Collections and Granules and their description. You will also see that while the elements are identical, some standards will include less information or different information based on the specific granule, such as that granules temporal extent. It is important to note that this is just a subset of what is in UMM-Common and the full list of elements found in UMM-Common can be from other objects (such as services and visualizations).
Element | Definition | Required |
---|---|---|
Spatial Extent | This element describes the geographic coverage of the data. | No |
Temporal Extent | This element describes when data were acquired or collected. | No |
Platform | This element describes the relevant platforms used to acquire the data. | Yes |
Instrument | This element is used to register the device that measured or recorded the data, including direct human observation. | Yes |
Project | This element describes the scientific endeavor(s) with which the collection is associated. | No |
Related URL | This element describes any resource-related URLs that include project home pages, resource information pages, services, related data, archives/servers, metadata extensions, direct links to online software packages, web mapping services, links to images, documents, or other data. | Yes |
Data Dates | This element is used to identify dates when the data or resource itself changed in some way. | No |
Use Constraints | This element defines how data may or may not be used to assure the protection of privacy or intellectual property. This includes license information, or any special restrictions, legal prerequisites, terms and conditions, and/or limitations on using the dataset. | No |
Access Constraints | This element describes any restrictions imposed on data access. Access Constraints can be described in a free text field with the option to provide an access control list (ACL) value. | No |
Metadata Language | This element specifies the language used in the metadata record (i.e. English, French, Chinese, etc.). | No |
Metadata Dates | This element is used to identify dates when the metadata changed in some way. This element is made of two sub-elements, Type and Date. | No |
Tiling Identification System | This element defines a named two-dimensional tiling system related to the collection. | No |
Additional Attributes | This element stores the data's distinctive attributes (i.e. attributes used to describe the unique characteristics of the resource which extend beyond those defined in this mapping). | No |
Language******** | The language used in the dataset (i.e. English, French, Chinese, etc.). Note: This is different from the language of the metadata. |
EXAMPLE HEADER FOR NEXT SECTION
While the information in the table above depicts shared elements in UMM-Common, the table below illustrates what the actual information looks like in the metadata. These examples will show how the information looks in both collections and granules as well as how the different metadata standards display their information that UMM then interprets and maps.
Examples of UMM-Common Metadata Information | |||||
---|---|---|---|---|---|
UMM-C | UMM-G | ||||
Element | Information | Standard | Element | Information | Standard |
Temporal Extent | <Temporal> <TimeType>Universal Time</TimeType> <DateType>Eastern Daylight</DateType> <TemporalRangeType>Long Range</TemporalRangeType> <PrecisionOfSeconds>1</PrecisionOfSeconds> <EndsAtPresentFlag>true</EndsAtPresentFlag> <RangeDateTime> <BeginningDateTime>1990-01-01T00:00:00Z</BeginningDateTime> <EndingDateTime>2003-12-31T00:00:00Z</EndingDateTime> </RangeDateTime> </Temporal> | ECHO 10 | Temporal Extent | <RangeDateTime> <BeginningDateTime>2006-01-15T00:00:00.000Z</BeginningDateTime> <EndingDateTime>2006-01-23T00:00:00.000Z</EndingDateTime> </RangeDateTime> **For single date/time*** <SingleDateTime>2002-02-27T23:49:24.0000000Z</SingleDateTime> | ECHO 10 (Different options available within ECHO 10 for granules, such as point, orbit, etc.) |
Platform | <Platform> | DIF 10 | Platform | <Platform> | DIF 10 |
Related URL | <OnlineAccessURLs> <OnlineAccessURL> <URL>http://sedac.ciesin.columbia.edu/data/set/ulandsat-cities-from-space/data-download</URL> <URLDescription>data download page</URLDescription> </OnlineAccessURL> </OnlineAccessURLs> <OnlineResources> <OnlineResource> <URL>http://dx.doi.org/10.7927/H4SQ8XB1</URL> <Description>data set DOI and homepage</Description> <Type>DOI URL</Type> </OnlineResource> </OnlineResources> <AssociatedBrowseImageUrls> <ProviderBrowseUrl> <URL>http://sedac.ciesin.columbia.edu/data/set/ulandsat-cities-from-space/maps</URL> </ProviderBrowseUrl> </AssociatedBrowseImageUrls> | ECHO 10 | Related URL | <OnlineAccessURLs> | ECHO 10 |
Metadata Dates | <gmd:dateStamp> <gco:DateTime>2008-12-02T00:00:00Z</gco:DateTime> </gmd:dateStamp> ... <gmd:date> <gmd:CI_Date> <gmd:date> <gco:DateTime>2008-12-02T00:00:00.000Z</gco:DateTime> </gmd:date> <gmd:dateType> <gmd:CI_DateTypeCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_DateTypeCode codeListValue="revision">revision</gmd:CI_DateTypeCode> </gmd:dateType> </gmd:CI_Date> </gmd:date> <gmd:date> <gmd:CI_Date> <gmd:date> <gco:DateTime>2008-12-02T00:00:00.000Z</gco:DateTime> </gmd:date> <gmd:dateType> <gmd:CI_DateTypeCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_DateTypeCode" codeListValue="creation">creation</gmd:CI_DateTypeCode> </gmd:dateType> </gmd:CI_Date> </gmd:date> | ISO 19115-2 | Metadata Dates | <gmd:dateStamp> <gco:DateTime>2008-12-02T00:00:00Z</gco:DateTime> </gmd:dateStamp> ... <gmd:date> <gmd:CI_Date> <gmd:date> <gco:DateTime>2008-12-02T00:00:00.000Z</gco:DateTime> </gmd:date> <gmd:dateType> <gmd:CI_DateTypeCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_DateTypeCode codeListValue="revision">revision</gmd:CI_DateTypeCode> </gmd:dateType> </gmd:CI_Date> </gmd:date> <gmd:date> <gmd:CI_Date> <gmd:date> <gco:DateTime>2008-12-02T00:00:00.000Z</gco:DateTime> </gmd:date> <gmd:dateType> <gmd:CI_DateTypeCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_DateTypeCode" codeListValue="creation">creation</gmd:CI_DateTypeCode> </gmd:dateType> </gmd:CI_Date> </gmd:date> | ISO 19115-2 |
Related Resources, Information, and Documentation
Here you can find further documentation about The Unified Metadata Model, UMM-C, UMM-G, UMM-Common, and other best practices regarding them. Information on this page was sourced and gathered from the following resources.
Unified Metadata Model:
UMM-C and UMM-G Wiki Pages
Miscellaneous CMR Resources
- CMR Introduction
- Earthdata Search Engine
- Global Change Master Directory (GCMD)
- CMR API Search Introduction
- CMR API Documentation
- Analysis and Review of CMR (ARC) Introduction