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GAlileo-Glonass Advanced Receiver INtegration

Final Report Summary - GAGARIN (Galileo-Glonass advanced receiver integration)

The GAGARIN project concerned the development of a Global Navigation Satellite System (GNSS) receiver for aeronautical applications in the Russian Federation. This project proposed to develop a Galileo-Glonass integrated capability in the GNSS receiver for aeronautic applications through an industrial cooperation amongst major receiver and antenna suppliers in Europe and in Russia, supported by key aeronautical research laboratory in Europe (DLR) and in Russia. In the context of the currently existing Global Positioning System (GPS)-Glonass solutions, this dual Galileo-Glonass capability was necessary to consolidate the adoption of Galileo by aviation in the Russian regions. The project contributed to the development of standardised worldwide GNSS solutions including Galileo in the pre-existing GPS and Glonass solutions, and paved the way to closer industrial and economic cooperation between Russia and Europe.

Project context and objectives:

Firstly, the GAGARIN programme provided background analysis that consisted in the identification of the political, industrial and market background, as well as the technical background. This analysis provided both a broad view on the use of the civil aviation GNSS receiver equipment in Russian Federation, such as political and regulatory elements, market elements and industrial elements and also provided the technical background of the GAGARIN programme with the identification of main characteristics and differentiators brought by Galileo and Glonass-K (the Glonass modernisation) and state-of-the-art analysis of key multi-constellation technologies at receiver, antenna and algorithm level.

Secondly, the GAGARIN programme investigated on innovative solutions to improve multi-constellation receiver to triple-constellation receiver through intensive service volume simulations to assess potential innovative triple-constellation receiver autonomous integrity algorithms performances, analytical study on a multi-band antenna design, and specification and design of the triple-constellation technological building blocks.

Finally, the first triple-constellation receiver mock-up for civil aviation in the world was designed, implemented and tested in order to demonstrate the technical feasibility of such device, taking into account industrialisation constraints. Similarly, as a test mean, the first triple-constellation radio-frequency (RF) signal simulator in the world was design, implemented and used to validate the correct functioning and performances of the receiver.

This was the result of a successful cooperation amongst the Russian and European industries. In parallel, awareness with both Russian Federation civil aviation institutes and EUROCAE standardisation body enabled to better understand the certification process, the Glonass constellation status and its modernisation plans, as well as the willingness of Russian Federation to implement triple-constellation receiver standard and promote their use in Russia. However, the same willingness was at that time not shared at EUROCAE level and outlined the need for strong political commitment from Russian and European institutions to encourage the development of common Galileo-Glonass standard. However, a first step to triple-constellation receiver standardisation was successfully done by GAGARIN programme that shown the technical and institutional feasibility of developing a triple-constellation standard.

Project results:

The main results of the project were the following:

- Standardisation of a GPS-Galileo-Glonass multi-constellation receiver: GAGARIN enabled to initiate this standardisation phase with Russian regulatory authorities. The next step was the drafting of the GPS-Galileo-GLONASS standard between the Russian authorities and EUROCAE dedicated working group.

- Innovative multi-constellation receiver autonomous integrity monitoring (RAIM) algorithms, with the aim of transferring integrity budget to user segment and taking benefit of multi-frequency multi-constellation signal processing to improve user segment integrity and relax ground and space segments constraints for reaching advanced aircraft navigation and approach operations. Proof of concept is reached by GAGARIN - at user segment - through the investigation of potential RAIM candidates, analytical evaluation of performances and algorithm refinement. The next step was both the implementation of RAIM candidates into breadboard and the refinement of RAIM algorithm concept in order to define and analyse the kind of required augmentation data at ground and satellite segments.

- Technological studies on both antenna and receiver sides:
(a) The studies performed in GAGARIN to assess compatibility on a triple-constellation antenna with Glonass requirements outlined compatibility issues between Glonass frequency division multiple access (FDMA) L1 and satellite communication systems and addressed design issues of an active multi-band antenna: the concept was formulated through the GAGARIN study to address such issues. The next step would be the actual implementation of an active multi-constellation antenna addressing the three GPS-Galileo-Glonass constellations.
(b) Mock-up development on receiver side in order to address feasibility issues and assess potential ways to facilitate competitive industrialisation of a multi-constellation receiver. The breadboard validation in laboratory of a Galileo-Glonass multi-constellation receiver was achieved by GAGARIN. The next step was to consider GAGARIN laboratory experimentation results for navigation system architecture definition and modelling and to use GAGARIN mock-up for real signal-in-space experimentations. Technological bricks of the GAGARIN mock-up needed to be refined in order to take into account aircraft environmental conditions, for example, through the use of application-specific integrated circuit (ASIC) technologies for enabling power consumption reduction, robustness to operational temperature environment and power consumption reduction.
(c) The GPS-Galileo-Glonass simulator mock-up enabled availability of the RF simulating tool required for the verification of future MCR products. The next step would be to consolidate the simulator design in order to comply with actual transmitted signal in space once actual modernised constellation would start to transmit GNSS signals and also to improve its reliability through extensive testing. Moreover, some additional features may be required to implement augmentations simulation tools.

Potential impact:

In the frame of the GAGARIN project, the results of the different studies conducted were disseminated. The expectations of the GAGARIN studies were presented at EUROCAE WG-62 and the interest for a combined Galileo-Glonass standardisation process was discussed. The attendance of Gosniian to EUROCAE WG-62 was planned in October 2010 and had to be postponed to June 2011.

An article was proposed to GPS world chief editor and the answer was pending. This article described the main challenges of the mock-up design and focused on the RF rejection mask and the advanced interference mitigation technique.

Exploitation of the results
Research and technological studies performed in the frame of GAGARIN paved the way to a future multi-constellation receiver product for civil aviation applications.

The multi-constellation receiver was identified by the European air traffic control infrastructure modernisation programme (SESAR), as a key contributor to air traffic control modernisation enabling the following:
- coping with the expected increase of en route traffic: expected to triple beyond 2020;
- coping with the objective to increase the air traffic safety by a factor of ten;
- coping with objectives of reduction of overall gas emissions and noise nuisance by reducing the average route extension per flight and by improving the terminal approach phase precision;
- improving low visibility procedures in order to facilitate approaches and landing in bad weather conditions;
- improving the airport throughput by limiting the time spent on the airport runway with the use of optimum break to vacate procedure, by reducing the aircraft separation in approach phase and by enabling parallel runway operations;
- improving surface navigation of aircraft by providing the aircraft crew improved positional awareness through the application of visual enhancement technologies like infrared camera on head-up displays with outline of the airport terrain in order to reduce the difficulties of transition from instrument to visual flight operations.

Nevertheless, the commercialisation of multi-constellation receiver depended on the availability of:
- operating modernised GNSS systems: Galileo, System for Differential Correction and Monitoring (SDCM), Multi-constellation Regional System (MRS), GPSL1/L5, Glonass-K;
- function and performance standards: modernised GNSS SARPS, Galileo MOPS, GPS-Galileo Conops, GPS-Galileo-Glonass-K qualification requirements;
- interface form and fit standards: aeronautical radio, incorporated (ARINC) for stand-alone modernised GNSS receiver, ARINC for MMR modernised GNSS receiver, other ARINC standards for others types of GNSS-based architecture.

Schedule for getting operating modernised GNSS systems was dependent on states' policy: only guess could be done at industrial level for availability of required operating system and industrials had to adapt their development plan accordingly.

Taking into account the status of modernised GNSS constellation deployment at that time, GAGARIN contributed to the definition of multi-constellation GNSS receiver foreseen to be commercially available close to 2020 once GNSS will be declared as operational for use in aeronautical domain. However, there would be many research and technology (R&D) steps that would have to be done before, as well as institutional willingness to cooperate into a combined multi-constellation standard.