Software Overview
The Data Hub Software (DHuS) is open source software developed by a Serco/Gael consortium to the purpose of supporting the ESA Copernicus data access.
The DHuS provides a simple web interface to allow interactive data discovery and download, and a powerful Application Programming Interface (API) that allows users to access the data via computer programs/scripts thereby automating/integrating the download within their workflow.
The figure below shows the High level DHuS Architecture.
DHuS Functionalities
The major functionalities of the Data Hub Software are schematically represented in figure below.
This function is activated by DHuS, which retrieves Sentinels’ products from an external data source.
this function is activated by external users who perform searches via four possible interfaces:
-Web-based Graphical User Interface (AJS);
-Open Web Component (OWC);
-Open Data Protocol (OData) interface;
-OpenSearch interface
The dissemination function manages the product dissemination, retrieval and access by the user. It also allows disseminating/retrieving sub-components of products. This is considered of particular relevance for the voluminous data products managed in the Sentinels mission.
This interaction, based on the OData protocol, allows a DHuS Instance (DHuS Front-End) to retrieve products and their metadata from another DHuS instance (DHuS BackEnd).
This functionality permits to the administrators to delete products from the archive and eventually to include a record in the DHuS Database which can be read by OData protocol in order to let operators and user to identify the deleted products and the deletion cause.
This function is in charge of managing the user accounts for access to the DHuS. It enables the definition of the roles and permissions of the users and prevents uncontrolled accesses. Moreover, it controls the data eviction and the system configuration.
The DHuS rolling archive is managed through control of the overall disk space available for EO products, the management of a general eviction policy and the creation of specific eviction rules governing the period during which products and collections remain available for dissemination prior to eviction.