GPS navigation systems will soon be able to guide users with centimetre accuracy thanks to a new data-processing system developed by American engineers.
Currently, GPS terminals are accurate to the level of one metre, which is only possible thanks to a network of ground-based reference stations as the primary satellite signal only offers an accuracy of ten metres.
However, the one metre accuracy currently available is still not enough for many emerging applications such as self-driving cars or precision farming.
"To fulfil both the automation and safety needs of driverless cars, some applications need to know not only which lane a car is in, but also where it is in that lane,” explained Professor Jay Farrell, from the University of California, Riverside, who led the research behind the new algorithm. “They need to know it continuously at high rates and high bandwidth for the duration of the trip.”
In a study published in the latest issue of the journal IEEE Transactions on Control Systems Technology, Farrell’s team describe how to achieve the accuracy levels required for autonomous driving applications by reformulating a series of equations that are used to determine a GPS receiver's position.
Farrell said these requirements can be achieved by combining GPS measurements with data from an inertial measurement unit (IMU) through an internal navigation system (INS). In the combined system, the GPS provides data to achieve high accuracy, while the IMU provides data to achieve high sample rates and high bandwidth continuously.
"Achieving this level of accuracy with computational loads that are suitable for real-time applications on low-power processors will not only advance the capabilities of highly specialised navigation systems, like those used in driverless cars and precision agriculture, but it will also improve location services accessed through mobile phones and other personal devices, without increasing their cost," Farrell said.
Previous attempts to improve GPS accuracy required several orders of magnitude more computations, increasing the cost and thus restricting feasibility of real-world applications.
The improved accuracy will enhance navigation services across the board, benefiting the aviation and naval industries, as well as mobile-phone based navigation on consumer smartphones and wearable gadgets.