The Proposal of the CBS Expert Team on Integrated Data Management for a WMO Metadata Standard Jürgen Seib Deutscher Wetterdienst Referat TI 13 e-mail: juergen.seib@dwd.de
Members of the Expert Team Dr. Steve Foreman, Chair Met Office, Bracknell, United Kingdom Alexander Besprozvannykh RIHMI-WDC, Obinsk, Russian Federation Guofu Wang China Meteorological Administration, Beijing, China Dr. Henry Hayhoe, representing CAgM Agriculture and Agri-Food Canada, Ottawa, Canada Gil Ross Met Office, Bracknell, United Kingdom Dr. Jürgen Seib Deutscher Wetterdienst, Offenbach, Germany Dienstag, 26. Februar 2002-2 -
Working definitions Metadata is descriptive data about data necessary to allow finding, processing and using data, information and products. A dataset is a collection of information (data, products, etc.) that the owner considers as a unit. One metadata record describes one dataset. Dienstag, 26. Februar 2002-3 -
WMO Requirements for a Metadata Standard (1) Current situation: WMO Programmes and Members maintain a tremendous volume and variety of metadata usually not standardised seldom distributed with data rarely processable by computers without additional software normally not readable and recognisable by humans when stored electronically Dienstag, 26. Februar 2002-4 -
WMO Requirements for a Metadata Standard (2) Task: development of a flexible metadata framework applicable for all WMO tasks at a general level extendible to special areas at specific levels no metadata repository of the all-inclusive form Dienstag, 26. Februar 2002-5 -
WMO Requirements for a Metadata Standard (3) Applications of metadata: Description and documentation Exchange of data and products Conserving / husbanding data Location / Discovery of data and products Making data and products available Processing or transforming data and products Dienstag, 26. Februar 2002-6 -
Existing relevant Metadata Standards ISO Draft International Standard 19115 Dublin Core standard Federal Geographic Data Committee (FGDC) standard Australia, New Zealand Spatial Information Council (ANZLIC) standard Directory Interchange Format (DIF) ISO 19115 would be the most appropriate basis XML would be the most appropriate representation form Dienstag, 26. Februar 2002-7 -
WMO Core Metadata Profile Dataset source or originator Keywords to identify the subject-matter of the dataset Unique dataset identifier Expanded date and time items (e.g. reference dates for creation, publication or revision date, metadata time stamp, validity time) Expanded description of geographic coverage Security or access rights Processing level (observations versus analyses) Distribution mechanisms Dienstag, 26. Februar 2002-8 -
Mandatory elements Title Identifier Reference Dates Responsible parties Abstract Keywords Geographic Extents Temporal Extents Topic Categories Metadata language Metadata character set Metadata Point of Contacts Metadata date stamp Access rights or restrictions Distribution mechanisms Lineage information Dienstag, 26. Februar 2002-9 -
Optional elements Spatial resolution Spatial representation type Reference system Vertical Extents Metadata file identifier Metadata standard name Metadata standard version Validity time On-line resources to define whenever applicable: Dataset language Character set Dienstag, 26. Februar 2002-10 -
XML Structures for Representing Metadata extensible Markup Language standard for describing structured data independent format for the exchange of data other standards are based on XML, e.g. SOAP, XSL many ways to represent WMO metadata in XML mapping the class structure of the ISO 19115 into an XML schema will be to complex Example Dienstag, 26. Februar 2002-11 -
Further Development review proposed standard with respect to existing datasets develop a list of keywords to describe WMO datasets develop a list of proposed extensions needed for ISO code lists propose XML schema, representation and examples investigate software to be used in implementation Dienstag, 26. Februar 2002-12 -
Summary A WMO standard for metadata is necessary its development is an urgent task there should be a simple WMO Core Metadata Profile and perhaps several specific profiles XML will be the best choice for the implementation of the standard it is difficult to develop an appropriate XML schema many efforts are needed for the transformation of existing metadata into the new standard Dienstag, 26. Februar 2002-13 -