Secure GBAS (Ground Based Augmentation System)
If you are in an airplane that is about to land, and there is bad weather, you want that airplane to safely find the runway. Many aircraft achieve this, every day, around the world using Autoland systems. One of the most advanced Autoland systems is the on Ground-Based Augmentation System (GBAS), which is based on the use of GNSS (Global Navigation Satellite System) signals (i.e. GPS, Galileo). It consists of a ground station with four reference antennas at carefully surveyed sites on an airport. This enables the generation of corrections for GNSS navigation signals which are transmitted to arriving aircraft. Together with these corrections the station also transmits integrity parameters that enable the aircraft to estimate its real-time navigation performance in order to ensure that the use of GBAS is safe for approach guidance down to automatic landings and rollout guidance on the runway
In recent years it has become apparent that not only GPS/Galileo are vulnerable to radio interference, but that the evolving nature of cyber-physical systems has even made GBAS vulnerable to tampering. That is something no Autoland system can tolerate: the error margins and the room for maneuvering are extremely small, for an aircraft approaching touchdown.
At DLR we are devoted to making GBAS robust against radio tampering, be it malicious or unintentional, so as to make all landings safe and secure.