Metadata
Metadata is commonly known as ‘data about data’. It is information about data that helps a potential data user understand whether a dataset is fit for a particular purpose. It is the information pertaining to a dataset or family of datasets, describing the name, format, context, content, structure and control of, or over, data. It may also provide information related to the purpose, quality, and location of the data as well as information related to its creation. In the context of IMOS, metadata records are items in a GeoNetwork catalogue.
Registered and indexed metadata also provides useful information items by which a user can search for, and discover datasets. Metadata is usually rendered in XML.
Metadata may also refer to the information made available in the header of a NetCDF file (a file format commonly used by IMOS). This is independent of the metadata records.
What is metadata used for?
Metadata provides:
- An adequate description of a dataset, so that someone other than the owner of the data can interpret it, and decide if the dataset may be useful,
- A way for the data to be found using a search tool.
A helpful analogy is a library catalog record. It offers essential information about a book or article, including its location and status. Additionally, it includes key details like the title, author, and keywords, making it easier to find relevant materials through a search engine.
ISO 19115-3:2018 Metadata Standard
The objective of ISO 19115 standard is to provide a model for describing information or resources that can have geographic extents. This section of ISO 19115 defines metadata elements, their properties, and the relationships between elements, and establishes a common set of metadata terminology, definitions, and extension procedures.
While the primary purpose of this part of ISO 19115 is to describe digital information that has a geographic extent, it can be used to describe all types of resources including textual documents, initiatives, software, sensors, non-geographic information, product specifications and repositories, i.e. it can be used to describe information resources that do not have geographic extent. This standard is maintained on github and is available by default in GeoNetwork 3.8+.
Controlled vocabularies
Controlled vocabularies can be used to populate specific metadata elements. These controlled vocabularies improve metadata management and record discoverability.
The AODN manage and employ the following vocabularies: