Thermal Inspections and Analysis
Simply explained, thermography measures surface temperatures using infrared video and still cameras. With these tools, light in the heat spectrum can be seen. Thermographic inspections can either be an interior or an exterior survey, with internal scans as the more common method.
This is because warm air does not always move through walls in straight line when escaping from a building.
Drones are applied across industries for a plethora of uses and thermal inspections and analysis are no exception to this. Thermal drones are being designed, developed, and adapted rapidly to cater for uses where thermal imaging is needed whether in construction, mining, electrical, surveillance, firefighting, search and rescue, and numerous others.
Thermal imaging drones make use of vision imaging cameras that can detect heat coming from almost any object or material. These are then turned into images and video, and often real-time, live-streams that can be viewed.
Thermal camera drones develop pictures or videos from heat and not visible light. Heat, or infrared thermal radiation, and light both form part of the electromagnetic spectrum. However, a camera that can detect visible light will not see thermal radiation, and a thermal camera cannot detect visible light.
With the right drone, thermal cameras can detect the smallest difference in heat, even as small as 0.01 degrees Celsius. The information that is captured with a thermal camera drone is displayed as assorted colours on a display, in thermal software or through various applications.
A drone with thermal cameras can capture images and differences in heat from:
- Living species including humans, animals, and vegetation.
- Buildings such as skyscrapers, factories, houses, and tents.
- Machinery such as engines, conveyor belts, and assembly lines.
- Airplanes, boats, vehicles, and all types under these.
- Electrical components such as circuits, power lines, capacitors, and all others.
- Land, rocks, and buoys which absorb light during the day and radiate it at night.
- Liquid and gas which emit thermal radiation which can be detected.
How thermal data is collected using thermal drones in South Africa ?
Flight planning is one of the major aspects involved with drone-based sensing. To capture quality aerial thermal images, an appropriate flight plan must be implemented. Before taking flight, the thermal sensor must be allowed adequate time to warm up.
To prevent thermal blur, a low flight speed must be maintained and there must be attention paid to climate, wind, and weather conditions. Thermal data which is collected from thermal drones is output into raster formats, with a choice between radiometric JPEG files and TIFF files.
Numerous organisations in South Africa are overcoming a variety of challenges by making use of thermal drones to collect thermal data.
When purchasing a thermal drone in South Africa, there are many factors to consider, some of which include the following:
- Detector resolution – higher resolutions will produce a clearer image.
- Thermal sensitivity
- Radiometric versus non-radiometric.
Frequently Asked Question
- Roof and building inspections
- Solar field inspections
- Electrical inspections
- Oil and gas applications such as refinery and pipeline inspections.
- Agricultural uses which includes temperature measurements to quantify crop diseases, insects, salinity, and several other factors that may lead to decreased yields.
- Road and bridge inspections
- Public safety and security
There are specific drones that are fitted with thermal cameras but not all drones have thermal imaging capabilities.
There are numerous reasons, but some revolve around the high detector resolution needed, the fact that thermal sensors are rare, and various features that thermal cameras have such as thermal and digital imagery, IR-Fusion features, and numerous other factors.
In most cases, thermal cameras can see as far as the eye, however, there are thermal cameras such as FLIR Systems that can detect the sun, which is more than 146 million kilometres away from earth.
No, not unless they are outside the window and even this will pose challenges due to glare and the distance required from the rotating props. Drones that use thermal imaging cannot see objects, they merely pick-up heat signatures.
In addition, there are also stringent measures and regulations in place to ensure that drones are not flown close to homes, unless there is permission granted by the owner.
Each has its own set of pros and cons and individual application and it will depend on the intended use.
- Aluminium foil
No, they cannot. Thermal cameras cannot see through walls as they are very thick and insulated, thus blocking any radiation from the other side. Thermal cameras merely detect the radiation of an object, they cannot see the object.