Drones have made a groundbreaking impact on our lives without us realising it. They are not mere tools of recreation for taking panoramic pictures and videos. They have far-reaching uses – from undertaking search and rescue operations and carrying out terrain mapping to detecting leaks in refineries – drones have plenty of real-world applications. Behind these wide-ranging applications is the altitude sensor for drones – a group of sensors that make it possible for UAVs to steer clear of obstacles and follow a clear path.
Types of altitude sensors commonly found in drones
The world is still new to the possibilities of unmanned flights. The use of drones has made life simpler but it’s important to address the concerns associated with their safe flights. Advancements in drone technology like altitude sensors and UAV thermal cameras have made sophisticated flights possible. Here are some important altitude sensors that enable drones to carry out successful flight operations.
- Altimeter: An altimeter is a sensor that measures altitude by utilising atmospheric pressure. It works on the principle that atmospheric pressure decreases with increasing altitude. Drones equipped with altimeters use this pressure change to estimate their height above sea level or a reference point. This method is effective for determining changes in altitude, but it may be influenced by weather conditions.
- Ultrasonic sensors: Ultrasonic sensors use sound waves to measure distance and altitude. They emit ultrasonic pulses and measure the time taken for the pulses to bounce off the surface and return. By calculating the time taken and the speed of sound, the sensor determines the distance to the ground or an object below. Ultrasonic sensors are commonly used for low-altitude hovering and obstacle avoidance.
- LiDar sensors: LiDAR (Light Detection and Ranging) sensors use laser light to create a detailed 3D map of the surroundings. They emit laser pulses and measure the time it takes for the light to reflect off objects and return. By calculating the time and using the speed of light, LiDAR sensors can accurately determine distances and create high-resolution elevation maps. LiDAR is particularly useful for mapping terrains and navigating complex environments.
- Barometric sensors: Barometric sensors, also known as pressure sensors, measure atmospheric pressure to estimate altitude. They rely on air pressure decreases with increasing altitude. Barometric sensors are quite accurate and can provide stable altitude readings even in changing weather conditions. However, they might require occasional calibration due to variations in atmospheric pressure.
- Gyroscopic sensors: This altitude sensor for drones, often referred to as gyros, measures the angular rate or rotation of the drone around its axis. While they don’t directly measure altitude, they are crucial for maintaining stable flight and orientation. By tracking rotation, gyros help drones stabilise themselves and maintain a consistent flight path, which indirectly contributes to altitude control.
- Accelerometer: Accelerometers measure the acceleration forces acting on a drone, including gravity. By integrating these measurements, the accelerometer provides information about the drone’s velocity and displacement. While not a direct altitude sensor, accelerometers are used in conjunction with other sensors (like gyros) to estimate changes in altitude and control the drone’s movements.
Use of UAV thermal cameras for complementing altitude sensors
Thermal cameras integrated into UAVs (Unmanned Aerial Vehicles) serve as valuable tools to complement altitude sensors in various applications. These cameras detect and visualise heat signatures emitted by objects, which provides a unique perspective that altitude sensors alone cannot offer.
- Search and Rescue: In search and rescue operations, combining UAV thermal cameras with altitude sensors enhances the ability to locate missing persons or survivors, even in challenging terrains or during nighttime. The thermal imaging capability allows drones to detect body heat, making it easier to locate individuals who might be hidden from traditional visual methods.
- Wildlife Monitoring: For ecological studies and wildlife monitoring, thermal UAV cameras are useful in tracking and studying nocturnal animals or hidden creatures that are otherwise difficult to spot. The combination of altitude sensors and thermal cameras enables researchers to observe wildlife behaviour and population dynamics from above without disturbing their natural habitats.
- Building Inspections: When conducting building inspections, especially for energy efficiency or identifying heat leaks, UAVs with thermal cameras provide a comprehensive view of temperature variations across a structure. This fusion of altitude data and thermal imagery aids in identifying areas of concern such as insulation gaps, electrical anomalies, or water leakage.
- Environmental Monitoring: In environmental surveys, thermal cameras on UAVs can help detect anomalies in ecosystems by highlighting temperature differences in bodies of water, vegetation, and land. These temperature variations can offer insights into ecosystem health, water flow patterns, and potential pollution sources.
- Security and Surveillance: Thermal cameras on UAVs play a vital role in security and surveillance applications. By combining altitude information with thermal imagery, drones can quickly detect and assess potential threats or intruders, even in low-light conditions or areas with dense vegetation.
- Firefighting and Disaster Response: During firefighting and disaster response efforts, thermal cameras on UAVs assist in locating and monitoring hotspots, identifying fire sources, and assessing the spread of flames. By flying at different altitudes, drones equipped with thermal cameras can provide valuable information to firefighters on the ground, aiding in strategic decision-making.
In essence, the integration of UAV thermal cameras with altitude sensors adds an extra layer of security to UAV operations. This combination enhances the drone’s capability to navigate any terrain with ease, gathering data and insights across various domains along the way. The combination of altitude sensors and thermal cameras makes them versatile tools for a wide range of applications, from humanitarian efforts to industrial inspections. The data is transmitted with the help of an onboard computer with installed software like UgCS (for planning various drone missions) and SkyHub hardware. The integrated system aids in accurate navigation in different kinds of terrains.