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Data Access service - CDI 

buoy_IMG_4011.jpg (76.1 K)The Common Data Index (CDI) was initiated in the Sea-Search project. As part of SeaDataNet it is being further developed and extended in data coverage to all SeaDataNet data centres and it is now also used in the Black Sea satellite project (Upgrade) BlackSeaScene. Its primary objective is to give users a highly detailed insight in the availability and geographical spread of marine data across the different data centres and institutes across Europe. The CDI provides an index (metadatabase) to individual data sets. Furthermore it provides direct online data access or direct online requests for data access or file downloads.

CDI V3
Currently, the Black Sea CDI V3 metadatabase contains more than 104.000 individual data entries from 11 Data Holding Centres from the 6 countries around the Black Sea, covering a broad scope and range of data, held by these organisations (originators may be other institutes!). In the coming months additional data centres from the BlackSeaScene network will further populate the CDI metadatabase and other institutes in their countries will be encouraged to participate.

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Querying CDI 
The CDI metadirectory can be queried and entries can be viewed by users. A versatile user interface, combining alphanumeric search criteria with a dynamic mapping tool, is available for users to specify their query requirements. The resulting entries, matching the query, are presented in a dynamic map and a browse list. This list allows for sorting on a number of key fields. Additional details per entry can be viewed by clicking on a Show button or by clicking on items on the map. The viewer includes a full screen presentation of each CDI entry. The names of the organisations involved are listed with hyperlinks, which provide the full address and profile description of the specific organisation. A special section of the CDI presentation lists details on the access restrictions of the data set. Data sets can be ordered by collecting them in the shopping basket and after that logging in (one time registration to SeaDataNet is needed) and then download them, if the access restrictions allow this.For more information on the full procedure of CDI V3 please check this page http://www.seadatanet.org/Data-Access

Maintenance of CDI and formats 
For purposes of standardisation and international exchange the ISO19115 metadata standard has been adopted. The CDI format is defined as a dedicated subset of this standard and ISO compliant. A CDI XML format supports the exchange between CDI-partners and the central CDI manager, and ensures interoperability with other systems and networks. CDI XML entries are generated by participating data centres (i.e. CDI-partners), directly from their databases. CDI-partners can make use of a dedicated Java Tool - MIKADO - to generate CDI XML files automatically, following a properties file, which defines the mapping between CDI-format and partner’s database fields and the required local queries. CDI updates are produced and transferred at regular intervals. Full documentation on the CDI format, MIKADO Tool and supporting lists can be found at: http://www.seadatanet.org.

Apart from that, all datasets collected via the system are provided in the same data fileformat: ODV for data profiles, NetCDF-CF for gridded data. This means that the datasets can easily be used in the ODV software, which is also available via the SeaDataNet website.