if set to quadcopter thermal imaging chamber, then it will turn into a powerful tool that can be used in construction, mining, electric power industry, surveys, fire extinguishing, as well as search and rescue operations.
A bit of theory
What is the thermal imager and infrared image?
All objects (above absolute zero) emit infrared energy depending on their temperature. Infrared energy is generated by vibration of atoms and molecules. The higher the temperature of the object, the faster its molecules and atoms are moving.
This movement is manifested in the form of infrared radiation, which human eye is not able to see, but our skin can feel (heat).
Thermal images are the process of using special infrared sensors of the chamber to illuminate the spectrum of light, invisible to the naked eye.
Thermal energy cannot be seen, and the principle of operation is always different: it can be absorbed, absorbing or reflected.
Infrared radiation is not able to see through objects, but can detect differences in the radiated thermal energy between the materials. This process is called heat transfer. Thus, thermal imagers are devices for contactless temperature measurement.
How does it work?
Outgoing infrared radiation focuses on an infrared sensor. From there it is converted into a visible spectrum of light, which our eyes are already able to see.
As a result, the thermal images may look different - it all depends on how they are reproduced in a visible spectrum.
What permission to choose?
There are many thermal imagers, but the most popular today are DJI Zenmuse H20T and Flir Vue TZ20. These cameras have a resolution of 640 × 512 pixels.
However, it is worth noting that the choice of permission ultimately depends on exactly how you are going to use the thermal imager.
640 × 512 is the most advanced and modern resolution, the main advantages of which are high image quality and a wide field of view.
The update frequency shows how many times a second the display can output a new image. The higher the update frequency, the less blurry is a picture.
An update rate of 9 Hz means that the thermal image is updated 9 times per second, and the display with a frequency of 30 Hz displays a new image 30 times per second.
The frequency of 9 Hz is excellent for most activities, since heat images are collected and then analyzed to verify malfunctions or any deviations.
The frequency of 30 Hz is ideal for search and rescue operations, since in this case you need to constantly scan the movement of objects. In addition, when using the camera with such a frequency, the chances of finding someone increase significantly, the rescue teams always write down the video, and then re-browsed it to see what was missed.
and the TZ20, and the H20T mentioned above have a 30 Hz update frequency so that the videos are updated as efficiently as possible and stable to achieve the best quality.
What is the radiation coefficient?
The radiation coefficient shows which efficiency the object gives its heat energy. This indicator depends on the type of surface, humidity, air and wind temperature.
These factors should be recorded and taken into account when conducting all necessary measurements. Objects with a high radiation ratio include people, animals, concrete, trees and stones. Low-coefficient facilities include shiny metals, such as aluminum foil and polished silver.
Isothermary is distinguished by predefined temperature ranges, so when a certain temperature is detected, they are allocated to orange.
Effects of the environment
The amount of thermal energy released in one or another situation has a direct impact on the infrared image. Usually the amount of infrared energy is associated with a daily cycle, solar load and thermal intersection:
- The daily cycle is a change in illumination, temperature, humidity and other environmental factors during the day.
- Solar load is when the surface absorbs more solar energy, and the temperature difference between objects decreases, as a result, disassemble things on Earth is harder.
- The thermal intersection occurs when the visible temperature difference between the specific object and the nearest environment decreases to such an extent that the camera cannot distinguish them.
Can infrared radiation see through glass?
Drones equipped with thermal cameras typically use mid- and long-wavelength infrared radiation, which cannot pass through glass and usually reflects infrared radiation. For this reason, thermal imaging lenses are usually made of germanium, since this element emits infrared radiation that can pass through glass.
Best thermal drones
DJI Mavic 2 Enterprise Dual
- Maximum flight altitude: 6000 m
- Maximum flight speed: 20 m/s
- Max Flight Time: 31 min
DJI Mavic 2 Enterprise Dual Equipped with with a dual camera mounted on a three-axis gimbal and a 4K sensor capable of capturing visible light. In addition, there is a FLIR Lepton IR module - a thermal micro-camera for obtaining thermal images.
Another advantage of the Mavic Enterprise is the various add-on modules (speakers, spotlight, beacon, etc.). It is important to note that the Mavic 2 Enterprise's FLIR thermal sensor has a rather low resolution, which means that the quadcoptermust be launched at a low altitude to obtain more accurate data .
DJI Mavic 2 Enterprise Advanced
- Maximum Flight Altitude: 6000 m
- Maximum flight speed: 20 m/s
- Maximum flight time: 31 min
If you are looking for a more compact drone and want to take higher resolution shots, DJI Mavic 2 Enterprise Advanced is definitely a step up from Dual.
The quadcopter outputs a higher image resolution (640 × 512 at 30Hz) for clearer image quality. The model has the same form factor as the Dual (compact and foldable), but with an improved thermal imager.
DJI Matrice 300 RTK
- Maximum airspeed: 23 m/s
- Maximum flight time: 55 min
Next in line is the DJI Matrice 300 RTK. The model has a transmission range of 9.3 miles and a maximum flight time of 55 minutes. In addition, it is worth highlighting the visual positioning sensor and the IP45 protection level (from moisture and dust).
Matrice 300 RTK is a reliable and durable drone, ready to work even in the most severe conditions. What makes the M300 even better, so this is the camera. We mean DJI Zenmuse H20T with 4 sensors: for thermal imaging, for wide-angle shooting, for television and laser rangefinder.
The best thermal cells
It all depends on what exactly you are going to do with drone. If you want to spend different checks or search for people, DJI Zenmuse XT2 is equipped with all the necessary configurations.
It is also worth noting the DJI Zenmuse H20T again. As we have already mentioned above, the model is compatible with DJI Matrice 300 RTK.
Thermal imager Workswell GIS 320 is an excellent option due to its compact sizes. However, the stabilizer is required for this model, and it must be individually integrated into the quadcopter itself.
Does the thermal imager can see the gas?
This concept is commonly referred to as the optical visualization of gases (OGI) and uses spectral filtering and various sensor optimizations to detect the absorbing and emission properties of various gas connections.
On the resulting image, the exiting gases look like smoke on a contrast background. Video can be viewed in real time and record for further tracking, archiving and reporting.
Once again, the WORKSWELL GIS 320 thermal imager is an excellent option due to its compact sizes.
Fire services are already using portable thermal imagers. Due to the drones with a thermal imaging camera, the crews can see fires in homes and forests in real time, since such quadrocopters are capable of seeing through the smoke.
In the case of forest fires, the ability to see through the smoke is crucial, not to mention the detection of smoldering hot spots that can flash.
In case of fires in buildings, the drone with a thermal imager can provide valuable information about the integrity of the roof, giving ground brigades on the speed and pathways of fire.
Checking the roofs
Remote sensing technology allows inspection personnel to conduct more thorough, frequent, safe and effective checks of roofs of buildings. Drones, equipped with infrared chambers, can be used to detect various disorders and water clusters.
With the help of a quadcoper with a zoom chamber, inspectors can visually identify problems, and it does not need to be physically there. As a result, it has a higher efficiency for the inspector when providing more accurate data to the client.