As the technology behind unmanned air vehicles (UAVs), or drones, continues to improve, the application of these highly versatile devices has expanded to almost every industry. For example, the use of drones has already proven successful in surveying and mapping large areas, inspecting a number of different industries including solar parks and energy plants, acquiring 360° spherical panoramic images for advertising, real estate and construction, monitoring plant and wildlife conservations, and much more1.
To further improve the sensitivity of drones in capturing specific aspects of some of the aforementioned applications, as well as improve the ability of drones to maneuver around difficult to reach locations, a variety of different sensors have been incorporated into these devices.
Types of Sensors for Drones
The specific type of sensor that a user will require for their drone will depend entirely upon the application in which the drone will be used and the specific data that will be collected during the UAV flight. Some of the most commonly used sensors that can be found in UAVs include:
Light-Pulse Distance Sensing (Laser)
A Laser Range Finder (LRF) sends out a laser beam at certain intervals. When these beams bounce off of objects, the LRF detects the time at which it takes for these beams to return to the drone to reflect the distance between the object and the drone.
Light Detection and Ranging (LiDAR): LiDARs create an LRF spin, which is especially useful for producing 3D constructions and surveillance required for aerial surveys and navigation purposes.
Radio Detection and Ranging
The frequency shift between a transmitter that emits a particular signal and the receiver antenna on the drone that detects its Eco is used to determine the speed and direction of the object in relation to the drone2.
Magnetic-Field Change Sensing
Sonar-Pulse Distance Sensing (Ultrasonic)
By sending out a sound wave at a specific frequency, the drone measures the distance by which a sound wave bounces off the object and back to the drone.
Image credit: dani3315/Shutterstock
Time of Flight (ToF) Sensors (Range Imaging)
Depth sensors of the ToF camera sensor emits a short infared light pulse. The pixels of the camera sensor measures the time in which the infared light pulse returns back to the drone.
ToF cameras are lightweight sensors that provide users with useful information on the distance between the sensor and an object at a sub-millimeter depth resolution.
Detects the heat that is radiating from almost all objects and materials to transform this data into images and videos.
Thermal Sensor Cameras are capable of capturing a wide variety of objects and organisms, as almost every source on the planet, as well as within the Universe, radiates some level of thermal energy. These include, but are not limited to, living species, buildings, planes, electrical sources, machinery, land, rocks, liquid, gas, etc3.
These types of sensors are particularly useful for the detection of chemicals present in environmental, industrial and emergency response situations. The use of chemical sensors on drones is especially critical in preventing the potential exposure of workers to the unknown chemical present in these situations.
Acelerometers sense movement of the drone through a variety of ways, which is entirely dependent upon the type of sensor integrated into the drone to achieve this purpose.
Inertial Measurement Sensors
By utilizing the multi-axis magnetometers installed within a drone, inertial measurement sensors can detect any changes in the drone’s direction and translate this data into a central processor that indicates the direction, orientation and speed of the drone to the user4.
- “UAV Applications” – Ascending Technologies
- “How Do Drones Work? Part 12 – Distance Measurement Sensors” – LinkedIn
- “10 Thermal Vision Cameras for Drones and How Thermal Imaging Works” – DroneZon
- “How Many Sensors are in a Drone, and What do they do?” – Sensors Online