The full set of attributes that make up an environment’s fingerprint are not visible at ground level – but from the air, they are a clear sign of where you are in the world. A new drone navigation system could use that information to accurately and precisely track its position over land.
The system, being developed in a partnership between Australian autonomous navigation specialist Advanced Navigation and European defence multinational MBDA, is designed to work even when GPS is not available.
“In an increasingly uncertain world where interference is becoming ubiquitous, commercial and military sectors can no longer rely purely on GPS for flight operations,” said Advanced Navigation CEO Chris Shaw as the company announced the partnership last November. “There is an urgent need for additional navigation aiding, to supplement platform inertial navigation and GPS receiver systems.”
Advanced Navigation and MBDA hope their biologically inspired system could meet that need using patent-pending technology from Bristol MBDA subsidiary Nileq. The technology of the same name uses ‘neuromorphic’ sensors, inspired by the structure and function of the human brain – but, in an age where artificial intelligence is seemingly everywhere, it is “free from AI-based methods” according to an MBDA spokesperson.
The sensors in question are event cameras, which offer ultra-high framerates. “With the neuromorphic camera, you're getting updates at sometimes thousands of times per second, because what it's measuring is the change in each pixel, rather than updating an entire image,” says Shaw to Professional Engineering.
“This information comes in much faster. At the same time, you're only refreshing what's changing in the image, so you have to process a whole lot less data.”
Attached to a drone flying above the landscape, the camera system will piece together the local ‘fingerprint’ by tracking landmarks and other features in the field of view. The images it collects will then be overlaid on an existing database of the Earth’s surface in a technique known as ‘map matching’, allowing the system to calculate its exact position.
As with other Advanced Navigation systems, which clients use to navigate in building sites, underwater and even on the Moon, Nileq will pair with the company’s inertial navigation system (INS) technology, which tracks position, orientation and velocity using internal accelerometers and gyroscopes. Once the neuromorphic system finds a match, it will feed it to INS, removing drift errors and the need for GPS.
The system will combine neuromorphic and inertial sensors
“By marrying the two technologies together, you get smooth, continuous position updates to whatever sort of aircraft platform is using the technology,” Shaw says.
The redundancy also means the system can keep working even if poor weather momentarily obscures the ground.
Changing landscape
Unlike our fingerprints, the landscape evolves and changes over time – sometimes gradually, and sometimes dramatically due to construction, natural disasters or destruction from war.
Thankfully, Shaw says, the new technology should be able to adapt to change in the same way as previous systems. “If someone, for example, grows a moustache or a beard or something like that, typically facial recognition can still [identify] that same person based on matching enough features. This uses similar principles really, where if it gets enough matches in a frame, it can determine with a high degree of certainty that it’s still in a specific area.
“Obviously if enough changed – for example, you're flying over somewhere and the entire area has been terraformed or something – it's not going to be able to get a position update. But essentially, a small amount of change in the image is going to be fine.”
While Advanced Navigation can provide customers with databases, Shaw suggests they could also download up-to-date imagery from providers such as Maxar. Users will load relevant local data for their areas of operation, he says, limiting the overall file size to something similar to the files used by car sat navs – “probably small enough to carry around, potentially on a thumb stick, if you want to update it”.
Limiting the file size of both the neuromorphic imagery and the databases means the positioning work can be completed on the drones themselves, without large hard drives.
“Nileq exploits the asynchronous [multiple simultaneous task] nature of neuromorphic imaging to achieve a visual navigation system that is data-light, computationally efficient and free from AI based methods,” says the MBDA spokesperson. “Together, these advantages enable a huge area to be searched very rapidly.”
The system also offers better range and stealth attributes than Lidar systems, Shaw adds.
Spoof-proof navigation
Navigation information from the system will typically be used by drone autopilots, Shaw says, with an initial focus on altitudes of 50 metres and above. The maximum altitude is limited by the lens, he adds, meaning stronger ones could be used to fly at higher altitudes.
The companies hope their technology could boost the safety of ‘beyond visual line of sight’ (BVLOS) operations in urban environments, agriculture, infrastructure inspections, offshore and environmental monitoring, search and rescue operations, disaster response, mining and construction.
Also potentially useful for manned aircraft, the system will likely find most use in places where GPS tracking is difficult – either because of technical issues or more nefarious reasons. On the one hand, Shaw says, “we're all familiar with walking down a very built-up city environment, and if we're using Google Maps, sometimes it says we're on the opposite side of the street because GPS can't quite position well enough in that environment.”
On the other hand is the reality of modern conflict. Russia has been accused of repeatedly disrupting GPS navigation in Eastern and Northern Europe since it invaded Ukraine, for example, jamming signals used by thousands of commercial flights.
Opsgroup, a membership organisation for workers in international flight operations, also reported a 500% increase in GPS spoofing in 2024. The technique, which was affecting 1,500 flights each day last August, transmits fake signals to trick receivers into thinking they are in a different location.
With heightened solar activity also joining the rank of threats to GPS signals, Shaw believes the combination of inertial and neuromorphic navigation could be in high demand as drone services expand in the years to come.
“When drones, especially aerial ones, become more common in urban environments, and regulations allow a lot more of them for things like drone deliveries… resilient navigation is definitely going to be a requirement from regulators,” he says.
“Being reliant on something like GPS to position when you can buy, on eBay, a $40 GPS jammer that anyone can just deploy, is obviously too unsafe. And so systems like this, which effectively can't be interfered with, allow building layers of resilience… we're not saying that something like this will just entirely replace GPS, but it adds that sort of redundancy and level of assurity on top of it.”
Flight tests are planned for early this year in Western Australia, with the system to be put through its paces above city, farmland and desert. The Australia-UK partnership then aims to commercialise the system in the second half of the year.
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.