The Sen2-Agri system is an operational standalone processing system generating agricultural products from Sentinel-2 (A&B) and Landsat 8 time series along the growing season. These different products consist of:
- monthly cloud-free composites of surface reflectance at 10 – 20 m resolution;
- monthly dynamic cropland masks, delivered from the agricultural mid-season onwards;
- cultivated crop type maps at 10 m resolution for main crop groups, delivered twice along agricultural seasons;
- periodic vegetation status maps, NDVI and LAI, describing the vegetative development of crops each time a cloud-free observation is recorded.
The Sen2-Agri system is free and open source, allowing any user generating near real time products tailored to his needs at its own premises or on cloud computing infrastructure. It consists in:
- A set of independent processing modules – one for each type of product and an additional one dedicated to atmospheric correction. The building blocks of the software solution for the modules rely on the Orfeo Toolbox (OTB), a high-resolution image processing toolbox, open source, portable and able to be extended to complement the suite of the already developed algorithms;
- An Orchestrator, a central component that manages the automated execution of these components from input EO data download through processing up to product delivery along the season basing upon user supplied parameters. Based on SLURM, an open source resource manager, It is also in charge of controlling resource allocation (memory, CPU) to execute jobs and dispatching them on execution nodes (i.e. a single machine or several ones whenever possible);
- A Graphical User Interface (GUI) designed to simplify the setting of mandatory parameters (site extent and season dates) or more advanced ones, to monitor the system activity, the pre-visualise the output products, to request additional products.
The level-3 and level-4 processing modules are fully compatible with the Sentinel-2 Toolbox and can be integrated in the common Sentinels Application Platform (SNAP) through external tool adapters, thereby allowing their usage either independently or as a processing chain outside the Sen2-Agri system.
Two main operation modes are available in the system:
- an automated mode, in which Sentinel-2 L1C and/or Landsat-8 L1T data are downloaded as they become available, and the processing chains are scheduled to execute accordingly;
- a user-oriented mode, in which a human operator can trigger the execution of any of the processing chains via a Graphical User Interface with custom configuration parameters.
The main goal of the system is to enable handling large volumes of EO data in a timely manner and to be easily scaled up to cover the whole region of interest. The Sen2-Agri system has been designed to facilitate the expansion of the hardware or software configuration without redesign and with almost no downtime, being able to support additional processing needs.