Research Study under SESAR Special Agreement No 1 for Lot 4 “Airborne and CNS Systems”
The Single European Sky Air Traffic Management Research Programme (SESAR) is a European initiative aimed at modernising and harmonising the European Air Traffic Management systems ensuring sustainable, safe and efficient development of air transport through a performance driven approach. The objective of the Special Agreement was to support the Members of SESAR Joint Undertaking with their contribution under the SESAR Programme related to the definition and validation of a multi-constellation multi-frequency GBAS system for precise airplane landing. The work of AT-One consortium (DLR and NLR) under the Special Agreement was focused on academic research in the fields of the utilisation of new GNSS navigation signals in GPS L1/L5 and Galileo E1/E5 bands in GBAS system, analysis of the threats to the nominal system operation occurring because of the signal distortions in ionosphere as well as due to multipath propagation and radio frequency interference. Also the aspects of the optimal multi-frequency multi-constellation signal processing in a navigation receiver of GBAS as well as monitoring of the system performance and integrity have been studied.
In the frame of the Special Agreement the members of AT-One Consortium provided academic-oriented support to SESAR Project 15.3.7 “Multi GNSS GBAS CAT II/III” and specifically to Task 3 “Preliminary Research Studies”. The members of AT-One Consortium are the German Aerospace Centre (DLR) and National Aerospace Laboratory (NLR, Nationaal Lucht- en Ruimtevaartlaboratorium) of The Netherlands. With their contributions DLR and NLR supported the development of a new generation of ground based augmentation system (GBAS) for precise airplane landing which makes use of satellite navigation signals from multiple constellations at multiple frequency bands, so called multi-constellation/multi-frequency (MC/MF) GBAS. In the frame of the project two satellite constellations of GPS and coming Galileo have been considered. The work of DLR and NLR was focused on the research areas which have not fully been covered by the expertise and capabilities of the permanent partners within SESAR 15.3.7 Project.
One part of the research efforts of DLR was aimed the assessment of the performance and optimal selection of new signals, in particular at GPS L1/L5 and Galileo E1, E5a/E5b frequency bands. The nominal performance of the signals was determined by conduction and analysis of high gain antenna measurements. The effects of non-nominal Galileo signals “evil waveforms” on the signal performance have been investigated .
Another important contribution of DLR consisted in the assessment of the impact of environmental threats on the performance of the new signals in the MC/MF GBAS context. In particular, signal distortions occurred during the propagation in ionosphere, multipath propagation and radio frequency interference have been thoroughly investigated by collecting and analysing the corresponding measurement data, by performing laboratory tests and field experiments .
Based on the obtained research results the concept of signal processing in the navigation receiver of MF/MC GBAS, the concept of measurement processing and appropriate integrity monitoring techniques have been defined.
 S. Thoelert, C. Enneking, M. Vergara, M. Sgammini, F. Antreich, M. Meurer, D. Brocard, C. Rodriguez, “GNSS Nominal Signal Distortions - Estimation, Validation and Impact on Receiver Performance”, In Proc. of ION GNSS+2015, Sept. 2015, Tampa, Florida, USA.
 A. Hornbostel, A. Konovaltsev, P.-Y. Dumas, “MF/MC Receiver Performance Evaluation under Nominal Interference Conditions for Definition of Receiver Parameter Space”, In Proc. of ION GNSS+ 2015, Sept. 2015, Tampa, USA.
 G. Rotondo, P. Thevenon, C. Milner, C. Macabiau, M. Felux, A. Hornbostel, M.-S. Circiu, “Methodology for Determining Pseudo-range Noise and Multipath Models for a Multi-Constellation, Multi-frequency GBAS System”, In Proc. of ION ITM 2015, Jan. 2015, Dana Point, CA, USA.
April 2013 – April 2015
Funded by SESAR Joint Undertaking
NLR, Thales Avionics, CNES