Our eyes see just a small section of all the electromagnetic waves around us. We call this portion “visible light,” and each range of the spectrum is assigned a name you’re familiar with: red, orange, yellow, green, blue, etc. But what’s above and below this visible chunk of the spectrum? You’re no doubt familiar with many of the invisible portions, even though you’ve never seen them: microwaves, radio waves, X-Rays, ultraviolet, and other too numerous to name.
How can these concepts help us see a person’s body heat in a dense forest? It turns out that just above visible light–with wavelengths longer than red light–is the infrared spectrum that contains the waves responsible for propagating heat. You’ve probably seen an iron rod heated until it glows orange, the light fading away as it cools. But even though the visible orange color is gone, the rod is still several hundred degrees and is radiating heat in the infrared spectrum. The visible colored light is gone, but the thermal light is still present and detectable by a thermal imaging drone.
Thermal Imaging VS Night Vision
Night vision cameras rely on magnifying available light and displaying it back to you. Since night vision relies on reflected light, there has to be some available light, such as the moon or a street lamp, or you can’t see a subject at all.
Instead, a thermal imaging drone can see in total darkness because it’s relying on heat generated by the subject itself, whether it’s a warm-blooded animal, a person or warm vehicle. Even tire tracks and footprints can often be picked up by infrared imaging sensors.
While thermal imaging units are fantastic tools, one must also understand that these cameras cannot see through walls or inside buildings as much of the internal thermal energy will be absorbed by the structure itself and represented by the pattern of absorption.
Assess Risk and Danger - Drones support firefighting operations by providing an overhead view of the scene of the fire, which gives firefighters real time information about how a fire is unfolding. When dealing with wildfires, drones can help firefighters understand how the fire is spreading and where it might go next. In dealing with a structure fire, drones can provide key information about exits and entry points, as well as revealing information about the nature of the fire that might not otherwise be possible to gather. Also, when a fire is starting to die out, it can still contain smoldering hot spots that are invisible to the naked eye, and a thermal camera attached to a drone can help firefighters find these spots and make sure to avoid them.
Respond to Disasters - Firefighters don’t only fight building/vehilce fires. UAVs can give firefighters a quick, safe way to capture information related to catastrophic events like floods, forest fires, and tornados. This early information helps incident commanders and emergency managers understand the magnitude of community impact on building infrastructure, road conditions, and living conditions. This information can help in determining what additional resources might be needed from the Canadian Red Cross, military, neighbouring communities, or other organizations. The data drones collect during disasters can also help find people trapped in their homes or vehicles, and divert rescue efforts to help them.
Save Lives - Using thermal cameras, firefighters can find people who might be trapped on an upper level of a building, or in a wildfire, and focus their efforts on saving them.
Create Pre-Fire Plans - Situational awareness is everything when it comes to saving lives and preventing damage during a fire, and half the battle is knowing what you’re walking into. That’s why firefighters can use drones to capture images and create orthomosaic maps of key buildings and facilities, like schools, within the areas where they work.These maps help firefighters to know where the exits are, and can be used by the incident commander during a fire to provide a comparison between normal conditions and fire conditions for different parts of a building.
Conduct Investigations - Using a drone to capture aerial footage while a fire is burning can provide a twofold value—one, the situational awareness of what is currently happening on the scene; and two, the collection of first-hand information about how the fire burned while it was active. This information, collected in photos and videos, can be archived and used for investigations into how the fire may have taken place. Firefighters can use drones after a fire has burned out to survey the scene and collect images that can be turned into orthomosaic maps. These maps serve as a record of the post-fire scene, so that even if the scene changes over time there is still a complete data set that can be used to investigate what might have caused the fire, and how it burned while it was active.
Create Training Materials - The aerial video footage and images captured while a fire is burning can be crucial in after-action assessments, in which firefighters critique their own efforts so that they can improve their approach and identify future training needs.These materials can also be used to train new firefighters, providing real life examples of how a fire might unfold, and where decisions on the ground were made well or could have been made better.
Search and Rescue
Drones are quickly becoming an irreplaceable tool for search and rescue. Whether it’s helping locate lost hikers, find missing animals and kids, or even helping adults with memory loss find their way home, drones can assist.
The value of professional drone services for search and rescue really shows in three main areas: responding quickly, allowing the use of sensors such as thermal imaging and zoom cameras, and providing automated search coverage of a precise grid.
Local police and volunteer SAR teams have long relied on helicopters and airplanes to aid in locating missing persons, but these options are both
expensive and slow. In contrast, drones are ready to fly in minutes, at a fraction of the cost of manned aircraft. Some drones, like our Matrice 300 RTK, can carry both thermal and visual sensors, meaning that you can locate people under almost any conditions. Flying with two distinct sensors, packaged into our hybrid H20T payload, allows viewing both heat signatures and visible information, like body heat in a forest or a hunter’s orange cap on a snowy mountain. Include the ability to mount a spotlight and loudspeaker, and you’ve got a well rounded aerial search unit.
Crime scene investigation - Drones can help crime scene investigation in a variety of ways. They can be used to collect evidence that may be difficult to reach from the ground. They can survey a crime scene and provide maps and 3D images within minutes. They can be used to provide lighting at night or low-light conditions. They can manually capture 60+ frames per second from a still camera, or record 4k video as needed. All this can be done in a fraction of the time it takes a ground unit to conduct this same investigation.
Accident Scenes - It is becoming more common now to use drones for 3D reconstruction of accidents. This is useful for multiple reasons. First, a drone can be launched to collect evidence from angles that were previously impossible without an expensive helicopter. Second, they can do this at multiple times the speed it would take to measure off everything on the ground. Third, they can collect evidence without blocking traffic. Utilizing Ground Control Points (CGPs) or Real Time Kinematics (RTK) systems can recreate the accident scene with centimetre level precision.