Airspaces used by European airlines in several areas of the world are subject to severe Global Navigation Satellite Systems (GNSS) degradations, outages and alterations. EASA has developed a tool to assess on a regular basis if it is sufficiently safe to operate civil transport flight operations in those areas, and to assess when an unsafe condition could be triggered. This tool works through analysis of different sources, including flight data broadcasted by aircraft and recorded by ground stations and satellites using the 1090Mhz Extended Squitter ADS-B (Automatic Dependent Surveillance – Broadcast) protocol. This contract is about the procurement of the ADS-B data required for the above assessment in the EASA tool.