Dear all,
after searching the mailing list archive without success, I would like to
bring up the topic of the ISO19115 metadata standard for geographical
information and how to best map this into CF. Obviously, the ISO standard
builds on XML and its hierarchical structures, while (global) attributes in
netcdf files are "flat". While "professional" applications can organize
databases and maintain proper links between metadata information in XML files
and data in netcdf files, the normal user risks loosing a lot of metadata
information if he relies solely on the content of the file. All that CF1.5
lists for the "Description of file contents" is:
"
title: A succinct description of what is in the dataset.
institution: Specifies where the original data was produced.
source: The method of production of the original data. [...]
history: Provides an audit trail for modifications to the original data.
[...]
references: Published or web-based references that describe the data or
methods used to produce it.
comment: Miscellaneous information about the data or methods used to produce
it.
"
As an example of the level of detail ISO19115 defines, here is an excerpt from
http://eden.ign.fr/xsd/isotc211/isofull/20090316/gmd/citation.xsd/view:
<xs:complexType name="CI_Citation_Type">
<xs:annotation>
<xs:documentation>Standardized resource
reference</xs:documentation>
</xs:annotation>
<xs:complexContent>
<xs:extension base="gco:AbstractObject_Type">
<xs:sequence>
<xs:element name="title"
type="gco:CharacterString_PropertyType"/>
<xs:element name="alternateTitle"
type="gco:CharacterString_PropertyType" minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="date"
type="gmd:CI_Date_PropertyType" maxOccurs="unbounded"/>
<xs:element name="edition"
type="gco:CharacterString_PropertyType" minOccurs="0"/>
<xs:element name="editionDate"
type="gco:Date_PropertyType" minOccurs="0"/>
<xs:element name="identifier"
type="gmd:MD_Identifier_PropertyType" minOccurs="0" maxOccurs="unbounded"/>
<xs:element
name="citedResponsibleParty" type="gmd:CI_ResponsibleParty_PropertyType"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="presentationForm"
type="gmd:CI_PresentationFormCode_PropertyType" minOccurs="0"
maxOccurs="unbounded"/>
<xs:element name="series"
type="gmd:CI_Series_PropertyType" minOccurs="0"/>
<xs:element name="otherCitationDetails"
type="gco:CharacterString_PropertyType" minOccurs="0"/>
<xs:element name="collectiveTitle"
type="gco:CharacterString_PropertyType" minOccurs="0"/>
<xs:element name="ISBN"
type="gco:CharacterString_PropertyType" minOccurs="0"/>
<xs:element name="ISSN"
type="gco:CharacterString_PropertyType" minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
I believe it would be nice if these two worlds could be better connected.
Obviously, an easy way would be via URI (for example in a global attribute
called iso19115 which would point to a location where the XML file can be
obtained). However, this is rather fragile and it would be nice to save the
extended metadata information in the file itself. One way could be an attribute
named xml (either global or variable attribute(s)" which would contain XML text
- this text could then identify itself as being ISO19115 compliant, for
example. A virtue of such a concept would be that automated data servers could
insert the "external" metadata information in the file upon delivery. Since the
present attributes to describe the file content are optional anyway, CF
wouldn't need to be modified much, except for mentioning the xml attribute and
its purpose.
If there are other ways to integrate ISO19115 and CF which have proven
efficient in practice, I'd be happy to learn about them.
Best regards,
Martin Schultz
= Dr. Martin G. Schultz, IEK-8, Forschungszentrum Jülich =
= D-52425 Jülich, Germany =
= ph: +49 (0)2461 61 2831, fax: +49 (0)2461 61 8131 =
= email: [email protected] =
= web: http://www.fz-juelich.de/icg/icg-2/m_schultz =
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Forschungszentrum Juelich GmbH
52425 Juelich
Sitz der Gesellschaft: Juelich
Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498
Vorsitzender des Aufsichtsrats: MinDirig Dr. Karl Eugen Huthmacher
Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender),
Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt,
Prof. Dr. Sebastian M. Schmidt
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