The ESA Data Dissemination System (DDS) enables the user to receive (pre-processed) images and derived products from MERIS, AATSR and ASAR within 24 hours after sensing the ENVISAT orbits acquired over Africa are transmitted. Derived products can be calibrated TOA radiances, reflectances, brightness, temperatures, cloud thickness, water vapour and other geophysical products. In addition, a set of other products - such as those produced in the framework of the Global Monitoring for Food Security (GMFS) project for early warning, agricultural mapping and crop yield assessment, covering eastern and western Africa and the 10 days maximum value composites derived from the SPOT-Vegetation instrument, e.g. the normalized difference vegetation index (NDVI) and the normalized difference water index (NDWI) - are dissemintaed when produced.

A newly developed plug-in is the “ESA-DDS toolbox”. It provides tools for automated archiving and pre-processing required to use the DDS data stream data in ILWIS. The design is identical to the GEONETCast toolbox.The toolbox currently supports data disseminated over Africa. In the near future, the DDS toolbox functionality will be expanded to include data disseminated for the European service.

Key Features are:

• fully open design and configurable by user
• ESA-DDS data management system for storage and retrieval of data
• BEAM is used to pre-process the ENVISAT data and routines are available to import the files in ILWIS
• other products disseminated, such as those delivered through the Global Monitoring for Food Security project and the 10-day SPOT Vegetation NDVI and NDWI products can be directly imported into an ILWIS format

All Toolbox functions can be coupled with and/or processed by other generic ILWIS RS and GIS functionality.

The ESA-DDS toolbox plug-in Graphical User Interface