It is possible to improve the accuracy of satellite navigation software so it pinpoints a location on Earth to within tens of centimetres without the need for new hardware, says a UK-based start-up.
Software that handles signals from global navigation satellite systems (GNSS) – such as the US government’s GPS or the EU’s Galileo – is ubiquitous in smartphones and other devices. But it only determines location to within a few metres.
“We have created the world’s first platform that is able to improve on this without the need for extra hardware,” says Jack Maddalena, CEO of UK start-up .
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Surveyors and other professionals have long used that can offer location precision of millimetres, but this extra accuracy is achieved by tapping into additional transmitters. Accessing these augmented services is expensive and requires special equipment – and it can take minutes to calculate such a precise location.
Naurt’s approach instead involves using software to minimise errors in the known orbital position of standard GNSS satellites at any given moment in time.
Although these orbital positions are known reasonably accurately, other factors come into play. The radio signals from the satellites can be slowed slightly when they interact with a region of the upper atmosphere known as the ionosphere. There are also small discrepancies in the satellite orbit and tiny inconsistencies in the timekeeping clocks on the satellites.
Naurt uses specific, precisely known locations on Earth as a calibration tool. It then compares these with the GNSS readings for those locations. An algorithm then deduces the error in each satellite’s signals. It can then use this information to calculate more accurately any given location on Earth from the satellite information, correcting both systematic and random errors.
What’s more, although Naurt gets the data to perform the calculations via the internet, it doesn’t require a continuous internet connection to establish a precise location. “We have offline and online solutions,” says Maddalena.
He says Naurt’s standard software boosts accuracy by between 40 and 90 per cent, but that better results are possible. One of Naurt’s first markets is online car rentals, where its “Naurt Drift” software will guide customers to the exact location of a parked vehicle.
“On average, GNSS drifts by 30 metres, and we can correct this to 20 centimetres on average,” says Maddalena. In one case the original GNSS location was out by 78 metres.
Previous software solutions such as the French Geoflex claim similar improvements, but Geoflex only works with certain Android phones. Naurt works with any receiver, and the general technique is well established.
“There are many variations on [such] algorithms, with various service providers, but [the approach] can achieve real-time positional accuracy of around 10 centimetres,” says navigation expert of Roke Manor Research, a UK communications company, suggesting Naurt’s claims are plausible. However, he notes that experimental data is needed to validate specific claims.
Precise location can ensure that vehicles observe parking restrictions and speed limits, and help keep self-driving vehicles in the correct lane. Naurt has carried out pilot schemes in the food delivery and vehicle rental sectors, and is rolling out the technology to commercial customers.
