Local Augmentation Systems

 Maritime GBAS at Research Port Rostock
zum Bild Maritime GBAS at Research Port Rostock
Augmentation systems are defined as systems that provide corrections  or data to reduce or eliminate errors of GNSS (Global Navigation Satellite System) signals. Such systems improve the accuracy, integrity, reliability and availability of GNSS-based positioning.

Ground Based Augmentation System (GBAS) also named Local Area Augmentation System (LAAS) describes a system that relies on so called differential techniques and use reference stations that continuously monitor the GPS signals. Since the positions of the reference stations have been precisely surveyed, the errors in the satellite signals can be calculated and corrections broadcast to users in the service area. The user's differential GPS receiver applies the corrections to improve the accuracy and integrity of its own position.

The development of GBAS\LAAS has been started in the late nineties. It was mainly driven by the intention of the aviation industry, to replace the Instrument Landing Systems (ILS and MLS) by a more flexible and cost-saving system. In parallel, and at approximately the same time, the IALA Beacon differential GNSS has been introduced in the maritime sector, replacing the LORAN-C terrestrial radio navigation system. DGNSS is now the primary navigation mean that meets the 8-10m harbour/harbour approach accuracy requirement of the International Maritime Organisation (IMO). Nowadays follow-up activities aim for the further development of DGNSS towards a maritime GBAS, able to fulfil the stringent IMO navigation performance requirements for port operations and automatic docking.

Fagi Demonstrator 200
Operator-Front-End of the experimental GBAS
The research and development activities of the Institute of Communications and Navigation of the DLR in the context of local augmentation are focusing on the further development of existing and development of new GBAS-systems for aviation and maritime applications. To support the GBAS development in both areas, as a test platform and for the demonstration of the obtained results the institute operates two experimental GBAS at two locations. The GBAS at the airport Braunschweig-Wolfsburg (Germany) currently consist of three GNSS receiver. They are used for:

  • The development of a GNSS-based CAT III CAT-II/III precision approach and landing system, and
  • The development of GNSS-based flight navigation and guidance systems for ground operations (taxiing).

The GBAS in the port of Rostock currently consist of one reference and one integrity monitoring station. Current research objectives in the maritime field are:

  • Development of an integrity concept for maritime applications, including code- and phase-based positioning methods,
  • Integration of GBAS and INS,
  • Development of assistance and guidance systems for high precise navigation and traffic management in the port vicinity.

Both experimental systems are used for the development and testing of new methods and algorithms for the estimation of position, integrity and error models. The platform for the development, validation and demonstration of the systems is the so called EVnet. It enables easy acquisition, processing, combination, management and distribution of the data within the different systems.

Dr.-Ing. Evelin Engler
German Aerospace Center

Institute of Communications and Navigation
, Navigation
Tel: +49 3981 480-147

Fax: +49 3981 480-123

E-Mail: Evelin.Engler@dlr.de
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