Global Navigation Satellite Systems (GNSS) are extremely useful in many different sectors, including transport. Europe declared the initial services of its own GNSS, Galileo, in 2016. It represented an enormous step forward in terms of performance, quality and diversity of service, as well as offering independence and autonomy to its users.

Unlike the United States’ GPS, Russia’s GLONASS and China’s BeiDou (with which, on the other hand, it is interoperable), Galileo is the world’s first GNSS that is designed specifically for civil use and with different user groups and services (e.g. open, high-precision, authenticated, governmental, emergency/search and rescue, etc.) in mind. It also offers unprecedented levels of accuracy and signal quality.

European projects such as RAILGAP, in which Ineco is taking part alongside Adif and CEDEX, build on previous research into the use of GNSS positioning. / PHOTO_MITMA

In the railway sector, GNSS-based applications can be used to optimise logistics, improve the management of rolling stock, and offer information services to passengers. At the same time, they also offer an inexpensive means of improving safety and supervision, by making it possible to replace physical ERTMS (European Rail Traffic Management System) balises with virtual equivalents. Using satellite positioning in conjunction with ERTMS will lower the cost of rolling out a system that the European Commission is currently deploying along the Continent’s main rail corridors –a task being coordinated by Ineco (see ITRANSPORTE 70)–, particularly with regard to regional lines and those with less traffic.

From physical balises to virtual ones

Along with Adif (Spanish Rail Infrastructure Manager), CEDEX (the Centre for Study and Experimentation in Public Works, which is part of MITMA, the Spanish Ministry of Transport, Mobility and the Urban Agenda) and a number of other international partners, in recent years Ineco has taken part in several European innovation projects designed to test and define the use of satellite technology in the railway sector.

To date, the tests that use trains in a real-world setting (such as the tests for the ERSAT GGC project in 2019; see ITRANSPORTE 68) have shown that Galileo is more suitable than the other systems. However, the technology still presents a number of technical hurdles that need to be overcome before commercial solutions can be brought to market. The geography of certain sections of line and the presence of elements such as tunnels, overpasses, natural obstacles and urban areas create so-called ‘shadow areas’ in the transmission of the GNSS signal, which in turn limits the operation of the virtual balises. There are also other problems derived from intentional interference, such as jamming or spoofing. However, the use of other technologies and navigation systems may help to resolve these issues.

The use of GNSS for railway operations depends to a large extent on the nature of the environment. For this reason, it is necessary to classify and identify the factors that contribute to operation under degraded conditions

The RAILGAP (RAILway Ground truth and digital mAP) project, which began in early 2021 and will continue until 2023, is a continuation of earlier research in this field. Part of the Horizon 2020 Programme and managed by the European Union Agency for the Space Programme (EUSPA), RAILGAP is led by the Italian railway infrastructure manager Rete Ferroviaria Italiana (RFI) and boasts numerous participants, including Radiolabs, Hitachi Rail STS, RINA, Trenitalia, ASSTRA, Adif, CEDEX, Ineco, DLR, Université Gustave Eiffel and Unife.

The project’s aim is to develop innovative, high-precision solutions that make it possible to obtain so-called ‘ground truth’ data and digital maps of the railway lines, which are essential in order to determine the trains’ positions efficiently and reliably. ‘Ground truth’ data will provide time-based geographical coordinates for the trains, along with dynamic variables such as speed and acceleration. To achieve this, it will be necessary to gather enormous amounts of train-related data, collected from various types of sensors, which will be used to improve mapping accuracy in ‘shadow areas’ such as urban areas, areas with lots of vegetation or trenches, etc.

The solutions proposed are based on the use of other sensors such as cameras, LIDAR and inertial measurements units, along with artificial intelligence (AI) technologies, to improve the positioning capacity provided by GNSS in ‘shadow areas’. Inertial sensors are used to detect the forces acting on the train, which makes it possible to estimate its movement over time; while optical sensors (cameras and LIDAR), combined with AI systems, make it possible to calculate the train’s position relative to key elements located along the track. In turn, this enables the train to be positioned with pinpoint accuracy, under optimal conditions.

The 30 satellites (24 operational and six spares) that will make up the Galileo system once its full operational capability is reached (initial services began in 2016) will be able to locate receivers with a margin of error of less than one metre. Additionally, Galileo is interoperable with the United States’ GPS, Russia’s GLONASS and China’s BeiDou systems.

RAILGAP will help to make the ERTMS –as well as the monitoring and control systems for the modernisation of regional and local lines– more sustainable, thereby reducing energy consumption.

Ineco is taking part in all of the project’s eight work packages and will lead the process of calculating ‘ground truth’ based on a solution involving the hybridisation of sensors. It also plays a major role in identifying and characterising the optical sensors required by the project, particularly cameras and LIDAR sensors. The activities that comprise work package 7, which focuses on the implementation of the digital map, will also draw on Ineco’s experience in applying AI to images in order to identify key elements, as it has done in other projects for Adif.

To this end, Ineco will develop the algorithms that make it possible to use the images captured by optical and stereoscopic cameras to recognise relevant elements on the track and position them using advanced image processing techniques and AI.

For its part, Adif is also working on all of the work packages, as well as operating a test vehicle (as it did previously for the ERSAT GGC project). The Railway Interoperability Laboratory from CEDEX (which is a world leader in ERTMS; see IT32 and 53) will focus on the architecture of the equipment inside the train and on the data collection phase, as well as the integration of the data in the laboratory.

RAILGAP proposes the use of cameras, LIDAR sensors or inertial measurement units, along with AI technology, to improve GNSS positioning in ‘shadow areas’.

Previous projects

Ineco, Adif and CEDEX have previously taken part in other research and innovation projects with a focus on GNSS applications in railways, such as ERSAT GGC (2017-2019), which also formed part of the Horizon 2020 programme (see ITRANSPORTE 69), and GATE4RAIL (2018-2021), part of Shift2Rail, a sector-specific programme developed by the European Commission to promote innovation in the railway industry.

The aim of the ERSAT GGC project, which involved 14 companies from five European countries, was to study the implementation of satellite technology in the ERTMS using virtual balises. To achieve this, a methodology was defined and several software tools were developed in order to classify a railway line with a view to implementing virtual balises along the length of the track.
The project also included some trials spread across three countries (France, Italy and Spain), where input data was gathered and later fed into the classification tool.

Additionally, 2018 saw the launch of GATE4RAIL, which aimed to improve the virtualisation of ERTMS tests based on satellite positioning. Ineco formed part of the consortium that carried out the project, which was led by Radiolabs (Italy) and also included RFI (Italy), Ifsttar (France), M3Systems (Belgium), Unife (Belgium), CEDEX (Spain), Bureau Veritas Italia (Italy) and Guide (France). Together, the consortium members developed a platform comprised of three blocks: GNSS, train and track. The challenge was to perform a simulation with modules from each block, located in different countries. In this project, which came to an end in 2021, Ineco’s role focused on system architecture and defining scenarios, in addition to providing data on obstacles via the GNSS4RAIL tool.

Challenges facing the use of GNSS in the railway sector

THE TRAIN OF THE FUTURE? A driverless train transporting minerals for the multinational corporation Rio Tinto in Pilbara, Western Australia. / PHOTO_RIO TINTO

For the railway sector, the use of GNSS presents a number of challenges of both a technical and cross-cutting nature. Cross-cutting challenges include those related to protection, cyber-security, legislation and regulation, standardisation, and speed of implementation; while the technical challenges include issues such as dealing with interference, the multipath effect, the integrity of the satellite signal, the overcoming of communication ‘shadow areas’ such as tunnels and mountains, highly complex lines that incorporate forks and junctions, and more precise recognition of parallel lines and stations.

With regard to the future of GNSS in the railway sector, a number of short, medium and long-term milestones have been identified. The most immediate goal is to be able to locate trains with optimum precision, as this will make it possible to increase track capacity. Another milestone is the development of virtual balises based on the continuous transmission of PVT data, which will reduce costs. Forthcoming developments also include detection of movement of rolling stock while the on-board ETCS is disconnected (this is known as cold movement detection, or CMD).

Medium-term goals include the development of ERTMS Level 3, whose defining characteristic is moving-block signalling. This technology will greatly increase the current ability to manage line capacity.

Long-term milestones include driverless trains, although a number of initiatives in this area –such as the Rio Tinto Driverless Cargo Line in Australia– already exist. This driverless line, known as the ‘robot train’, incorporates 1,700 kilometres of track and 220 monitored locomotives. It records 12 GB of data traffic per day and uses automatic train detection logic based on ERTMS Level 2. Using this architecture, the multinational mining corporation Rio Tinto has developed predictive models that can detect potential failures in upcoming operations and recommend maintenance activities. As one would expect, final approval of these activities lies with the technical personnel.

The annual World ATM Congress (WAC) event plays host to product demonstrations and launches, contract closures and networking opportunities, together with a busy schedule of conferences and high-level meetings. This year, a total of 225 exhibiting companies and 7,500 delegates from 130 countries took part. Every year, the World ATM Congress brings together around a hundred air navigation service providers (ANSPs), product developers, leaders and experts in the aviation industry, government representatives, manufacturers and industry suppliers from around the world.

Organised by the Civil Air Navigation Services Organisation (CANSO) –of which Enaire (formerly Aena) is a founding member and which brings together air navigation service providers from around the world– in partnership with the Air Traffic Control Association (ATCA), an association that represents the air traffic control sector, the World Air Traffic Management Congress is an indispensable event that Ineco has been attending for almost 20 years.

The Galileo system: the brightest star

Galileo is the flagship project of European satellite navigation: a Global Navigation Satellite System (GNSS) that will boast a total of 30 satellites by 2020 –26 of which are already in orbit– managed by the European Global Navigation Satellite Systems Agency (GSA). Galileo is compatible and interoperable with systems such as the US’s GPS and Russia’s GLONASS, and will offer an unprecedented improvement in performance in terms of precision, resilience and robustness.

In 2016, the GSA entrusted its operation and maintenance to a consortium led by Spaceopal for the following 10 years. Spain is part of this consortium, through a group of public enterprises led by Ineco, in partnership with Isdefe and INTA (National Institute of Aerospace Technology). Ineco is in charge of the operation, top level maintenance and management of the hosting services of the European GNSS Service Centre (GSC) located at the INTA’s facilities in Torrejón de Ardoz (Madrid).

Orderly skies

With a marked international orientation, the air navigation sector moves in a world of extreme safety requirements and resulting advances in new equipment and technologies to ensure this safety.

Since 2007, Ineco has been part of the Single European Sky ATM Research (SESAR) project, which is currently in the deployment phase of unifying space and air traffic control in Europe. In this respect, WAC 2019 played host to SESAR guided walking tours which saw the involvement of Ineco’s aviation experts Pilar Calzón, Víctor Gordo, Fernando Ruiz-Artaza, José Manuel Rísquez, Mercedes López and José Recio. There were also presentations on the integration of small drones and their application in airports and CTR environments by Víctor Gordo, and on the HEDIPRO flight procedure design tool by the engineers Javier Espinosa Aranda and Fernando Carrillo, also from Ineco.

The company has extensive experience in calculating and designing aeronautical charts for the publication of procedures based on PBN, GNSS, GBAS and vertical guidance approaches (APV SBAS), airspace restructuring –such as the restructuring carried out at Spanish airports and in countries of the likes of Egypt and Morocco– and navigation easement studies. Designs of instrumental flight procedures for the international market are also carried out, such as those implemented for the airports of the Sultanate of Oman, Cape Verde and Singapore Changi Airport.

In addition, in partnership with ENAIRE (formerly Aena), Ineco has carried out more than 2,000 radio simulations to assess the impact on airport CNS systems of infrastructures close to airports, such as shopping centres and housing developments, and within the airports themselves, for instance, new terminal buildings and runway extensions. To achieve this, the company uses its own NAVTOOLS proprietary software.

RPAS: all of the guarantees for drone flights

Ineco’s RPAS radio navigation aid verification project, which was presented during WAC 19, is an innovative solution for in-flight recording of radio navigation aid signals and a console on the ground that makes it possible to determine the trajectory flown and quality of guidance provided by the radio navigation aid.

The company is certified to operate and owns a light commercial drone for inspection of bridges and viaducts, and has also acquired a drone with greater capabilities and autonomy able to carry payloads of up to 4 kg, enabling more complex operations to be carried out.

From SACTA to iTEC

In terms of automated air traffic control systems, Ineco has historically worked in collaboration with Enaire and other industry partners on the evolution and development of its control system, known as SACTA, which
was designed entirely by Spanish companies and is a benchmark at the European and global levels. The SACTA and ICARO systems and the ACC voice communication system (COMETA) provide all aeronautical information necessary for air traffic control in Spain and are constantly updated.

The company is currently collaborating with Enaire on the development of a future automated air traffic control system (iTEC). Ineco is also working on another fundamental element for air navigation safety: guaranteeing the quality of the aviation data that ENAIRE collects, publishes and supplies.

In July, Jesús Silva, president of Ineco, met with Olavo Correia, minister of Finance; Eunice Silva, minister of Infrastructure; and José da Silva Gonçalves, minister of Economy and Employment in Cape Verde. Ineco has collaborated with Cape Verdean authorities since 2003 on projects such as the enlargement and modernisation of the international airports Boavista and Sal, and the renewal of the tread surface at Praia International Airport. The company has also worked on the master plans for Cape Verde’s four international airports.

Additionally, in 2015 Ineco was awarded the tender for the inspection of passenger terminal enlargement work of Boavista and Sal, design of Global Navigation Satellite System (GNSS) procedures for Boavista and São Vicente airports, and the master plans for local aerodromes which will be used in planning how they will develop their airport network and in facilitating the development of tourism on other islands of this archipielago.