Drones in SAR - the power of the hive mind

In search and rescue (SAR) operations, time is of the essence. The first 72 hours can be vital in the search for a missing person; rescuers may need to cover large areas and navigate rough and inhospitable landscapes when searching. In 2017 in England and Wales alone, nearly 20,000 man hours of SAR operations were spent searching. But, what if we could use technology to reduce that and help people be found faster?

UAV use moving with the times

Drone and unmanned air vehicle (UAV) technology has come a long way since its original purpose of removing people from military missions considered too dangerous or inappropriate for human pilots. It is now increasingly used to assist rescue services in operations, particularly for searching, as drones can quickly reach vantage points humans cannot easily access. Across the world, drones are being used for this very task and, combined with developments in imaging technologies, can be powerful tools in search operations.

Lochaber Mountain Rescue Team, for example, regularly uses aerial drone footage to help find injured climbers and walkers in Scotland. Adding a highpowered search light to a drone can provide a welcome light source during nighttime rescues. Search and rescue teams based in a mountainous region of the US have already used drones with lighting to find and save trapped hikers in Snowy Canyon State Park after dark. In addition to traditional light sources, thermal imaging has also been used in a range of scenarios, like finding a person who had been thrown clear of their car in an accident at night time. This technology can help save lives. But it is not just people that drones can be used to detect and observe.

In emergency scenarios, such as fires or building collapse, the structures need to be regularly monitored and assessed to mitigate any harm to trapped persons or crews. Using a drone to survey and assess the structural soundness of large structures and buildings provides emergency and rescue services with the confidence to act quickly when working with a burning or collapsed structure. Adding a thermal imaging camera provides a good way to safely monitor fire hotspots within a building, find people under rubble and track crews and people to be rescued.

Using drones to do as well as see

As drones become more powerful and are available in a greater range of sizes, they can be used for a greater breadth of activities beyond SAR surveillance. Airborne vehicles have a clear role to play, particularly in the speed of response, with the advantage of using a drone in an urban setting estimated to be 120 per cent when direct line speed, traffic advantage and field of view are all taken into account. In addition, compared to manned aircraft used for inspection, drones have the advantage of lower resource requirements, and can be deployed in large numbers.

One area that airborne vehicles can help is in the delivery of medical supplies. A project called Gold Dragon, run in partnership with the Welsh Ambulance Service, has shown a proof of concept for the delivery of a mini defibrillator via drone to remote or rural locations that would otherwise be difficult to reach quickly in an ambulance.

They also have an important role to play in larger deliveries. Windracers has developed a large drone with a double engine and fixed wings, which can be used to carry essential equipment and humanitarian aid in emergency situations. The ULTRA UAV has a carrying capacity of up to 100kg, which is impressive for its type, and will help teams to deliver aid and resources faster, more cheaply and to pinpointed locations.

Pushing the boundaries of drones in rescue scenarios

So far, it’s all been fairly familiar ground to tread. What’s coming next for drone operations though, is a lot more exciting. And it’s coming in the form of a swarm.

The Future Flight Challenge is funding the SWARM project with Windracers, which is developing systems to enable multiple drones to fly in close formations and work with each other to act in emergency situations. This swarm technology is built on the ability of UAVs to cooperate in groups of up to a hundred while also reacting to their local environment, and neighboring UAVs. They are designed so that they do not need to be directed by a central control station, which means that the solution is more scalable and that large numbers of drones can be called on in a crisis. It also makes the system more robust in the face of individual robot or ground station failure.

This advancement in drone swarms raises new challenges in the design of the underlying algorithms that coordinate UAVs throughout deployment. For this to work effectively, the drones need to be able to respond and react in time-critical scenarios, refuel and enable loading via in-air navigation and coordinate with each other. That’s in addition to safely coordinating the delivery of payloads.

As such, testing is crucial to the success of this technology. The algorithms that sit behind a swarm can be developed in realistic digital twin environments that allow us to test what will happen in a simulated version of the environments SAR teams might face. The SWARM project, for instance, uses a digital twin that allows for single-click transfer of swarm controllers from simulation to reality, so that we can test and be confident in its deployment during an emergency. Two use cases are initially being developed through this process, centred around humanitarian aid delivery and forest fire mitigation, but by its end, the project aims to have demonstrated a proof-of-concept flight with an initial five UAVs.

The possibilities of this SWARM technology in SAR are vast. If a hiker goes missing in a national park, drones could interact with other drones in the pod, allowing them to rapidly and effectively obtain information on which ground has not been covered yet – even more so than one drone in operation. In firefighting situations, especially wildfires, multiple drones can locate the hotspots, directing firefighters to the essential areas that need to be handled, to make an area safer for SAR teams. The SWARM technology could even be used to carry water or fire suppressant via a group of drones, removing the need for firefighters to even enter dangerous areas.

What's next for SAR teams and airborne technology?

By its very nature, the future of SAR will need to incorporate drones to save more lives and create safer scenarios for crews. History has so often seen man and machine working together to accomplish great things, and it is clear that drones can be a powerful tool for finding missing people, delivering crucial resources in hard-to-reach areas, and acting on evolving hazards.

Our learning from the experience of those that trained for, and are closely involved in, front-line emergency situations will underpin the success of these advancements. It is vital that these potential game-changing technologies in SAR operations are not developed separately from the sector. While the Future Flight Challenge is paving the road (or flight path) towards a future where SAR teams gain an unparalleled edge with airborne technologies, we want to get SAR teams involved to make sure UAVs can be used to their fullest to support crews on the ground.