Metadata is data that provides information about the actual data, but not its content.
How does Metadata look like?
Metadata of geodetic data and products can contain several types of information. That can consist of general descriptions like title, data format, version, date, link to the data, contact person, … and of detailed descriptions like antenna type, receiver type, analyzing method, used models, …
What are Metadata Standards?
To make metadata comparable it is beneficial to use common metadata standards / schemas such as a simple Sitelog, GeodesyML, ISO19115, Dublin Core Format, etc.
How can Metadata be provided?
Geodetic metadata can be made available in the internet via various ways:
- That could be a simple website where the geodetic data is described. In this case it is favorable to provide the metadata in a machine-readable format (e.g. XML or JSON). This is used, for example, for DOI metadata or GeodesyML.
- Another way is to provide a metadata file (e.g. *.txt, *.log, Sitelog, …) on a server which can be accessed via (S)FTP or HTTP(S) request.
- A provison of metadata by standardized Interfaces or API is also possible. There are several standards in use (e.g. OAI-PMH interface, RESTful interface, OGC web feature service, …). This allows easy synchronization (harvesting) of metadata for metadata portals like the GGOS Portal.
What are DOI’s for Geodetic Data?
To make geodetic data and products FAIR (Findable, Accessible, Interoperable and Reusable) it is advantageous to assign DOI (Digital Object Identifier) for them (e.g. http://doi.org/10.5880/ICGEM.2019.011). This allows citability and scientific recognition.
Looking more closely at DOIs for geodetic data, they consists of metadata provided in a standardized metadata schema and available on a website (landing page) that is also machine-readable (e.g., XML format). If you want to read more, please visit the page of the GGOS Working Group on DOI’s for geodetic Data Sets.
