In September 2015, two more Galileo satellites were launched on a Soyuz rocket from French Guiana. Their successful placement in orbit brings the number in the constellation to ten, a third of the way to a full network of 30.
Galileo is Europe’s global navigation satellite system, designed to complement the American Global Positioning System (GPS). It is set to provide real-time positioning accuracy down to the metre.
Although the European navigation system will not be fully operational until 2020, some smartphones and car navigation devices equipped with compatible chipsets can already receive the signals from the satellites that are now in orbit 23,222 kilometres above Earth.
Now new technological advances mean Galileo could be the trigger for a step change in ‘Train Location Management’ that will revolutionise the rail industry, and transform the passenger’s journey.
An Innovation that Could Change the Rail Industry
In 2013, the author led project T990 for the UK RSSB (Rail Safety and Standards Board)1 while with another organisation. This project set out to develop a high level strategy on train position, and to define a common Train Location Service (TLS), that brings coherence to the provision of trainbourne and trackside positioning capability rather than allowing individual solutions to emerge on the rail network. The TLS would utilise core technologies which deliver signalling safety, train detection and scheduling functions, integrating and enhancing their outputs to provide the basis for a range of beneficial end-user applications.
The TLS would combine location data from all available sources and make it available to any applications needing positional information, such as train control centres or smartphones. It would work independently of locator technology and of the applications making use of location data and would therefore embrace new digital technologies, as and when they are developed.
As part of this study, we explored the readiness of the telecommunications industry and in particular Global Navigation Satellite Systems (GNSS), or more commonly ‘sat-nav’, to provide the supporting technology. Despite a favourable response, implementation has been slow, but new technological advances are changing this.
Sat-nav can pinpoint the geographic location of trains and transmit the information on board the train, in real-time, without the need to cross-check it with the electronic beacons2 fixed on the rail line, as explained below. This has the potential to become a very valuable source of train location information, which is not yet available with current train tracking systems.
This kind of sat-nav locator is already being used by train owners and operators. However, it is limited to providing a geographical position which is not necessarily precise enough to give an accurate location on a given track when tracks, or station platforms, are close together (called track/platform precision or “discrimination”).
Integration of Sat-Nav Derived Train Location Data with Infrastructure-Derived Data
Where track precision is required, current technology depends on there being something (such as a beacon), which adds to the sat-nav’s data. This approach has been adopted by some operators to provide “discrimination”, but these solutions are generally “ad-hoc” and switch from one location technology to the other rather than providing a fully integrated solution. This approach also entails substantial additional infrastructure costs in fitting and maintaining the track beacons, and the on-board technology to read beacons or balises3 is also expensive.
The real benefits and savings come if sat-nav derived train location data is integrated with infrastructure-derived data in a central database without the need for these additional beacons. This centralised approach would deliver improved and more consistently accurate location readings along the route. Integration of these two types of data will create higher levels of accuracy. This capability is already being used to some extent in Project COMPASS, a system being developed to enable trains to continue to move when the current signal system fails, and by ORBIS4, but not yet on a fully integrated scale.
The Train Location Service would be capable of tracking the following information for each train:
- Train service identity
- Time of last fix
- Location of train - geospatial (latitude/longitude) and mapped to track
- Direction (heading)
- Train length
Information would be tracked in real time and updated whenever new information comes into the system from either the infrastructure or the train. The TLS would need to provide transparent access to information derived from other systems including DARWIN (the UK’s real time train prediction application) and operator databases containing train consist, orientation, etc. Supporting information may also be needed, for instance on door status (open/closed).