Over the past few years, unmanned aircraft systems (i.e. drones) have been increasingly and creatively employed in search and rescue (SAR) missions across the world. There are many case reports and news articles from the past few years that demonstrate this technology’s efficiency and effectiveness in SAR. Earlier this year, a SAR drone equipped with an infrared camera was able to locate a missing 70-year-old man with dementia lost deep in the woods outside Seattle in the middle of a bitterly cold night. The SAR team on the ground below had walked past the missing man earlier in the night and were ultimately only able to pinpoint his location in the dense brush with the help of the drone’s heat-sensing capabilities. In 2020, a drone with optical gas imaging and thermal sensors aided first responders in narrowing their search area for a missing child in North Dakota by ruling out locations in which no thermal activity was detected. German researchers are even developing a SAR drone with sophisticated microphones and algorithms designed to triangulate the screams of missing hikers in order to pinpoint their exact location.
The U.S. Department of Homeland Security has also realized the potential efficiency and cost-effectiveness drones can offer community search and rescue efforts and have helped groups decide on which drones to purchase through the First Responder Robotic Operations System Test (FRROST) program. This program allows teams to test drones under real-world conditions with simulated scenarios, thereby helping them to choose a drone that makes the most sense for their budgets and projected drone use. Drones have been used with such success in the past few years that drone service providers and first responder drone experts have started to conduct missing people training scenarios and can even be hired to locate injured persons in complicated search and rescue scenarios.
Given the utility, expanded use, reduced cost, and life-saving capabilities of drones in SAR scenarios, they have been the subject of new research focused on their potential to expand and perhaps even reshape the way in which search and rescue is carried out. In one study using twenty simulated SAR operations, traditional SAR foot patrol was compared to a drone technique in finding a missing person. They found that drones were superior with a total median search area nearly three times greater than traditional foot patrol and a median time to arrival at the simulated missing person of less than nine minutes compared to nearly an hour clocked by foot patrol. A 2019 study found that the simultaneous use of three drones was able to find a target over twice as fast compared to when a single drone was deployed in one SAR mission. Newer prototype drone software is attempting to test how well drones can locate missing persons in heavily forested areas: in seventeen field experiments in forested areas, researchers found that onboard thermal image processing and adaptive drone flight paths shortened mission search times and reliably found missing persons in dense coverage.
A case report from 2017 posited that because drones are equipped with recording devices they could also be used for debriefings and provider education regarding recorded rescue missions. It is even possible that larger drones could be used to deliver life-saving equipment such as automated external defibrillators or tourniquet materials to SAR crews otherwise outside the reach of land vehicles.
Despite these exciting new implications for drones, the limitations of their expanded use must be considered. Drones are classified under the Federal Aviation Administration which has installed strict requirements and regulations for their use and certifications for flying in the US. Additionally, because drones may be used near manned aircrafts, SAR coordination with local aviation centers may be necessary to reduce interference. On top of that, drones equipped with cameras and transmitters are limited by their power source and may have only a short duration of flight time. These challenges will continue to limit the scope of drones in the near future but with the increasing advances in this technology and continued funding and partnership amongst local agencies their potential is only growing. Ongoing research into creative applications of drone technology will be vital in continuing to yield the cost- and life-saving benefits of this new frontier in SAR.