Satellite based Navigation Systems (Global Navigation Satellite System GNSS) will become a major element in
the navigation infrastructure of the future. In addition to classical en-route and terminal navigation, where GNSS is
increasingly used, approach and landing procedures are being developed and implemented based on GNSS. To meet the
requirements of integrity, accuracy, continuity and availability for precision approach and landing operations, augmentation
systems are needed. Currently there are two augmentation systems for these periods of flight available: Ground Based
Augmentation Systems (GBAS) and Space Based Augmentation Systems (SBAS). This paper will focus on GBAS research
projects conducted by the Technische Universität (TU) Braunschweig, Institute of Flight Guidance (IFF), and the German
Aerospace Center (DLR) Braunschweig, Institute of Flight Guidance (FL). While TU Braunschweig is working mainly in
the domain of navigation technology (both ground and airborne) DLR (namely Robert Geister) is concentrating on the
procedure design and implementation of special approach procedures