An interface for users
One of IR OZCAR’s objectives is to set up a single portal providing transparent access to metadata and data from all IR OZCAR observatories in accordance with FAIR (Findable, Accessible, Interoperable, Reusable) data principles. The proposed architecture was defined after consultation with future users and local IT teams, resulting in a distributed architecture where search criteria included geographical extent, time window, geology, climate, data providers, funding institutions and variable names (Braud et al., 2020). This last criterion was highlighted by users as one of the most important to implement among all the search criteria in the web interface. It was therefore necessary to inventory and harmonise the variable names, which were initially classified according to a hierarchical vocabulary derived from the GCMD (Global Change Master Directory) and were subsequently used to implement the I-ADOPT framework, which allows variable names to be broken down into atomic elements, making it easier to implement semantic interoperability (Coussot et al., 2024).
For interoperability reasons, this vocabulary has been published on the Web (https://in-situ.theia-land.fr/skosmos/theia_ozcar_thesaurus/en/ ) and links have been provided to ontologies relevant to the field. The Theia/OZCAR IS provides various standardised services, based on the wealth of information provided by the pivot data model. These include the standard metadata/data exchange protocols defined by the OGC (Open Geospatial Consortium): CSW (Catalog Service for the Web), the SensorThings standard for time series.
To date, almost all the observatories have implemented the pivotal data model, and a web interface was put into production in 2019, which has been continuously improved since then thanks to feedback from users. It can be accessed with recent versions of Firefox and Google Chrome (http://(https://in-situ.theia-land.fr/). A web cataloguing service has also been set up, making the datasets present on the Theia/OZCAR portal visible on the Theia portal.
The team is continuing to support all the observatories in the Fairisation of their data, developing data exchange services (SensorThings) and offering users the possibility of downloading data from the Theia/OZCAR portal in harmonised formats. The pivot data model will also be extended to all types of data, as only point-in-time time series have been processed to date.
An ANR ‘FairTOIS’ project (Implementing FAIR principles for Theia/OZCAR in situ data information system), funded by the ANR FLASH call for tenders (Agence nationale de la recherche) and running from March 2020 to December 2022, has provided some of the human and financial resources needed to develop the Theia/OZCAR IS. The Data Management Plan for the Theia/OZCAR IS can be consulted here https://dmp.opidor.fr/public_plans?page=1&search=theia%2FOZCAR
More information on the Theia/OZCAR IS : https://www.theia-land.fr/product/donnees-in-situ/