The current international standardized and widespread Instrument landing system ILS is supposed to be replaced by a successor system in future. The ILS has reached a high conceptual and technical level, which allows performing safe landings under difficult conditions (regarding weather and environment conditions). A further extension of the ILS leads to various problems, caused by the small number of available frequency channels or the increasing compactness of airport constructions.
The global Navigation Satellite System GNSS provides a worldwide localization in time and position. On the 11th Air Navigation Conference the implementation of the GNSS for all flight phases was set.
To achieve the Required Navigation Performance (RNP), extensions (augmentations) of the key system are necessary.
It was the objective of the LINA project to establish the prerequisites for a launch of the future satellite-based, precise landing system. They focused on components for use on the ground and on-board of the so-called Ground Based Augmentation System GBAS.
Das Subproject about the ground components deals with system analysis and qualification of a reference station. The qualification is an important step towards a successful authorization.
The LINA project was divided into several work packages: Program Management, GBAS Ground Station, on-board components, Integrity & Prop. Error Simulation, Performance Analysis, Flight Test & Evaluation
To fulfil the above mentioned objectives, various tests and the construction of a prototype of the GBAS-station were planned.
For the various work packages, the following results were achieved:
- GBAS Ground Station: major overhaul (including system and safety analysis) of an existing Ground Station for experimental purposes. In a further step, software and hardware were adjusted towards the new conditions. In conclusion, the new system specifications were tested successfully.
- Integrity & Prop. Error Simulation: Various tests on signal interference were made: What type of errors occur? What happens there in detail? Are there possible ways to limit these errors?
- Performance analysis: This work package included a model and simulation of the GPS receiver, monitoring of the “signal in Space”, and the development of a simulation tool for signal propagation.
- Flight Test & Evaluation: After completion of the development activities of the LINA project, a validation of the capability of the system was needed. Various tests on the ground and during flights proofed that the performance requirements were met.
Findings of the study are published by a final report (German only), which is available online via the Technical Information Library (TIB) of the Hannover University: http://edok01.tib.uni-hannover.de/edoks/e01fb11/672735822.pdf