Data & Processing

EO Data Software based services

 

Sen4CAP on CREODIAS

Introduction

The Common Agricultural Policy (CAP) of the European Union aims at improving the European agricultural productivity in a sustainable manner while ensuring a decent standard of living of farmers within the EU. Sen4CAP system has been developed has been setup by ESA to develop an end-to-end processing and analysis pipeline aimed at the European and national stakeholders of the CAP, providing them with validated algorithms, products, workflows and best practices for agriculture monitoring relevant for the management of the CAP

The Sen4CAP software is available as open-source freeware and is very well suited to be run in a cloud-computing environment. Recently, CREODIAS has developed a VM image on which the Sen4CAP software is installed and checked. When this image is installed on a CREODIAS VM, any user can run the Sen4CAP software, benefitting both from direct access to the complete Copernicus Sentinel satellite data repository and dynamically scalable processing opportunities of the CREODIAS cloud computing environment.
 

The Sen4CAP system

The Sen4CAP system consist of a Earth Observation (EO) processing system linked with a visualization tool. It is open-source, allowing any user to generate, at his own premises and in an operational way, products tailored to his needs. The Sen4CAP EO operational system is a standalone processing chain which generates a set of products for agriculture monitoring from Sentinel-2 (S2) L1C, Sentinel 1 (S1) Single Look Complex (SLC) and Landsat 8 (L8) L1T time series. These agriculture monitoring products consist of:

  • cultivated crop type maps, generated several times during the agricultural season and delivered 10 days after the end of the acquisition period;
  • biophysical vegetation status indicators consisting of Normalized Difference Vegetation Index (NDVI), Leaf Area Index (LAI), Fraction-Absorbed Photosynthetically Active Radiation (fAPAR) and the Fraction of Vegetation Cover (FCover) describing the vegetative development of crops;
  • grassland mowing product, generated at regular intervals during the agricultural season and delivered 5 days after the acquisition of the last image of the interval;
  • agricultural practices monitoring product, generated at regular intervals during the agricultural season (with a main time step at the end of the period of required compliancy according to the national Ecological Focus Area (EFA) definition) and delivered 5 days after the acquisition of the last image of the interval and one month after the end of this required compliancy period.

The Sen4CAP EO system is composed of a set of independent processing modules orchestrated by a data-driven approach. These modules are composed by a set of tools which can be re-used into other systems. The logical data flow and the main interfaces of the Sen4CAP operational system is provided in Figure 1.
 

 

 

Figure 1: Operational workflow Sen4CAP system

Setting up Sen4CAP on CREODIAS

Sen4CAP runs in a Linux CentOS environment and needs a few steps to be installed properly. In order to facilitate the use of Sen4CAP, a VM image of CentOS 7 with Sen4CAP has been prepared for CREODIAS. When a user wishes to use this VM, it can simply be selected as the image source during the Sen4CAP VM configuration.

As soon as the VM is set up and accessed (through X2Go Client for example), the Sen4CAP system can be started through a web browser or the command line and a new project can be defined.

As soon as a new project is activated, the Sen4CAP orchestrators start collecting satellite data and pre-processing. The great advantage of running the system on a CREODIAS VM is that there is no need to download any Sentinel-1 or Sentinel-2 data, the Sen4CAP orchestrator queries the database, creates symbolic links to the satellite data on CREODIAS and starts the pre-processors straightaway. As the pre-processing of a large number of satellite images takes considerable resources, it takes some time for first images to appear.