Researchers of Vrije Universiteit Amsterdam, Delft University of Technology, and VSL announced on Wednesday, November 16, the development of an alternative positioning system that is more robust and accurate than GPS, especially in urban settings.
As per the researchers’ claims, the working prototype achieved an accuracy of 10 centimetres.
What are GPS and its limitations?
The Global Positioning System (GPS) is a space-based navigation system that provides location and time information in all weather, day or night, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.
However, researchers debate that these US GPS or EU Galileo, which rely on global navigation satellite systems, have limitations and vulnerabilities. The researchers also add that their radio signals are weak when received on Earth, and accurate positioning is no longer possible if the radio signals are reflected or blocked by buildings.
“This can make GPS unreliable in urban settings, for instance,” says Christiaan Tiberius of the Delft University of Technology and project coordinator. “Which is a problem if we ever want to use automated vehicles. Also, citizens and our authorities depend on GPS for many location-based applications and navigation devices. Furthermore, so far, we have had no backup system.”
SuperGPS
Dubbed SuperGPS, the project aims to develop an alternative positioning system that uses the mobile telecommunication network instead of satellites.
‘We realised that with a few cutting-edge innovations, the telecommunication network could be transformed into a very accurate alternative positioning system independent of GPS”, says physicist Jeroen Koelemeij of VU Amsterdam. “We have successfully developed a system that can provide connectivity just like existing mobile, Wi-Fi networks do, as well as accurate positioning and time distribution like GPS.”
Researchers do it by connecting the mobile network to a very accurate atomic clock to broadcast perfectly timed messages for positioning. These connections are made through the existing fibre-optic network, claim the researchers.
“We had already been investigating techniques to distribute the national time produced by our atomic clocks to users elsewhere through the telecommunication network,” says Erik Dierikx of VSL.
“With these techniques, we can turn the network into a nationwide distributed atomic clock – with many new applications such as accurate positioning through mobile networks. With the hybrid optical-wireless system we have demonstrated now, anyone can have wireless access to the national time produced at VSL. It forms an extremely accurate radio clock up to one billionth of a second,” he adds.
Furthermore, the system employs radio signals with a much larger bandwidth than common.
“Buildings reflect radio signals, which can confuse navigation devices. The large bandwidth of our system helps sort out these confusing signal reflections and enables higher positioning accuracy”, Gerard Janssen of the Delft University of Technology explains.
“At the same time, radio spectrum bandwidth is scarce and expensive. We circumvent this by using several related small-bandwidth radio signals spread over a large virtual bandwidth. It has the advantage that only a small fraction of the virtual bandwidth is used, and the signals can be very similar to those of mobile phones,” he adds.
According to the researchers, the SuperGPS can be used in various location-based applications, including automated vehicles, quantum communication, and next-generation mobile communication systems.
You can check out the full paper here.
