GNSS

GNSS (Global Navigation Satellite Systems) includes core constellation systems (like GPS, GLONASS and the future GALILEO and Beidu), and augmentation systems such as Aircraft Based Augmentation Systems (ABAS), Satellite Based Augmentation Systems (SBAS) – like EGNOS in Europe – and Ground Based Augmentation System (GBAS).

GNSS is a key technology of the communications, navigation, and surveillance (CNS) infrastructure. GNSS can support navigation applications in all phases of flight as well as surveillance application like ADS-B. GNSS is also used in safety nets like the GPWS (Ground Proximity Warning Systems) and provides the time reference that is used to synchronise systems and operations in ATM.

GNSS is essential to the introduction of PBN. This already supports RNAV 5 and RNP APCH operations in ECAC and will enable the deployment of other applications based on RNP navigation specifications like Advanced RNP, RNP 0.3 and RNP 1 operations.

With the objective of mitigating the growing dependency on GNSS and getting the best from GNSS-based applications, the EUROCONTROL policy on GNSS and the European ATM Master plan set a vision based on GNSS multi-frequency and multi-constellation with improved performances.

Related links

For more information on GPS, GLONASS, GALILEO and EGNOS please refer to the following pages:

EUROCONTROL activities

 EUROCONTROL plays a central role in the introduction of GNSS in the European aviation based on partnership with aviation stakeholders, other European institutions dealing with GNSS (EC, ESA and GSA) and international partners like the FAA. 

 The following key principles apply to our work on GNSS:

  1. the Agency should ensure the protection of the interests of all aviation users working in consultation with aviation stakeholders, notably airspace users;
  2. the Agency’s approach and involvement on different GNSS systems should be based on its ability to provide benefits to ATM Network performance in terms of capacity, cost efficiency, safety, environment and/or interoperability, with respect to other solutions;
  3. the Agency can provide valuable, independent and impartial support to the EU in finding how best EGNOS and Galileo can be integrated into the aviation strategy to enhance ATM performance of the SES. 

EUROCONTROL contributes to SESAR projects related to GNSS such as 15.3.4 (GNSS baseline) and 9.27 (GNSS Multi-constellation receiver).

The following tabs illustrate EUROCONTROL activities on the various GNSS areas.

GBAS

EUROCONTROL contributes to GBAS by:

  • representing the European perspective at the global level within ICAO and at industry fora;
  • supporting to the development of international standards as well as providing a manufacturer-independent data evaluation toolset called PEGASUS allowing unbiased assessment of products from competing manufacturers for the validation of requirements;
  • contributing to SESAR on every package relating to GBAS (SESAR WP 15.3.6 and 15.3.7);
  • jointly chairing with the FAA the International GBAS Working Group (I-GWG), which provides a biannual working forum on GBAS;
  • animating the EUROCONTROL LATO focus group which oversees the GBAS activities and provides a forum to discuss Precision Approach related issues;
  • having addressed how to transition from ILS to GBAS based on an economic assessment, an operational assessment and from a safety and security perspective.

SBAS

EUROCONTROL contributes to SBAS by:

  • representing the European perspective at the global level within ICAO and the SBAS Interoperability Working Group and at industry fora;
  • representing aviation users need at the EGNOS Mission Requirements Document Configuration Control Board;
  • supporting to the development of international standards as well as providing a manufacturer-independent data evaluation toolset called PEGASUS allowing unbiased assessment of products from competing manufacturers for the validation of requirements;
  • running the EGNOS Data Collection Network (EDCN). EDCN is a standardized data collection environment established by EUROCONTROL to perform continuous EGNOS performance monitoring. This network was created in 2001 in preparation for the EGNOS Signal in Space validation, and it was an important contribution for the EGNOS Service provider Certification process coordinated with the European Commission. Find out more about EDCN and its bi-monthly newsletters on the EDCN website as well as in this EUROCONTROL Top Story;
  • addressing SBAS system related aspects together with SBAS-based operations related aspects in the context of the EUROCONTROL NSG and RAiSG groups.

ABAS

Aircraft-Based Augmentation System (ABAS is achieved by features of the onboard equipment designed to overcome the performance limitations of the GNSS constellations. The two systems currently in use are Receiver Autonomous Integrity Monitoring (RAIM) and the Aircraft Autonomous Integrity Monitor (AAIM). RAIM may be either Fault Detection (FD) or Fault Detection & Exclusion (FDE).

ABAS/RAIM is a GNSS-based navigation technology that is widely used in aviation. GPS/RAIM relies on the integrity information broadcast by GPS satellites and the RAIM algorithm, which raises the integrity level of the navigation solution to meet the aviation requirement.

The RAIM algorithm performs a consistency check of the position solution: it requires a sufficient number of GPS satellites in view and a favourable geometric arrangement of these satellites. GPS/RAIM availability prediction can be computed with the AUGUR tool (http://augur.ecacnav.com/).

Future RAIM algorithms will take advantage of the multi-frequency and multi-constellation GNSS to increase current performance and have the potential to provide vertical integrity worldwide.

EUROCONTROL contributes to ABAS by:

  • representing the European perspective at the global level within ICAO and at industry fora. Providing RAIM predictions on the AUGUR website;
  • proposing a RAIM NOTAM proposals service in the catalogue of service of EAD. Information can be obtained directly from the EAD Service Desk.
  • helping to take full advantage of on-board mitigation techniques, especially those based on inertial navigation systems;
  • participating in the US-EU group on Advanced RAIM where extension of RAIM to multiconstellation and multi-frequency context is being discussed;
  • addressing ABAS related aspects together with applications using ABAS (PBN applications) in the context of the EUROCONTROL NSG and RAiSG groups.

Vulnerabilities

EUROCONTROL contributes to various projects aimed at assessing the GNSS vulnerability and identifying the appropriate mitigation actions. So far, two threats with an impact on GNSS have been identified: ionosphere events and interferences.

Within the ionosphere study, EUROCONTROL:

  • monitors the ionosphere through using the existing network of GNSS ground station;
  • characterises and models the ionosphere events which would impact GNSS operation;
  • simulates the ionosphere impact on the GNSS receivers and on the GNSS operation through a dedicated simulator which is mainly based on PEGASUS;
  • identifies potential mitigation actions;
  • raises awareness within the aviation community;
  • supports the development of international standards regarding the use of ionosphere information in support to aviation.

Within the interference study, EUROCONTROL has classified interference sources and has set up potential interference scenarios. The various scenarios identified are: the use of the Personal Privacy Device, the industrial or commercial in or out band emissions, the portable electronic devices inside the aircraft, the intentional jamming and finally, the use of GNSS repeaters. For each of these scenarios, an impact assessment has been performed and the potential mitigation actions have been identified.

 

Institutional and legal issues

EUROCONTROL is addressing institutional and legal issues related to GNSS, such as the applicability of the SES regulations to GNSS.