Image Source: Coal Mine Fire UAV Drone China is a major coal-producing country that consumes large amounts of coal every year. Due to the existence of many small coal kilns using backward mining methods, numerous worked-out areas have been formed. The coal mines were abandoned with no mitigation, so […]
China is a major coal-producing country that consumes large amounts of coal every year. Due to the existence of many small coal kilns using backward mining methods, numerous worked-out areas have been formed. The coal mines were abandoned with no mitigation, so air penetrates into the roadways and contacts the coal seams; as a result, the residual coal seams spontaneously ignite to form coal fires. These coal fires have burned millions of tons of valuable coal resources and caused serious environmental problems. To implement fire suppression more effectively, coal fire detection is a key technology. Thermal infrared remote sensing from unmanned aerial vehicle combined with a surface survey is used to identify the range of coal fires in the Huojitu coal mine in Shenmu city.
A coal fire is a subsurface phenomenon that causes not only losses of valuable natural resources but also environmental problems, such as surface cracks, subsidence and collapse, and atmospheric pollution, eventually endangering human security. The term coal fire refers to a spontaneous combustion phenomenon in which a coal body is in contact with air and oxidizes to burn under natural conditions that occur in exposed coal seams or underground, so as in coal waste and storage piles.
Accurate detection of the coal fire combustion centre, range and depth is a major problem for coal fire exploration technology, and it is also the basis of coal fire suppression projects. It is difficult to determine the extent of underground coal fires because of a few surface factors, including vegetation, rock and soil cover over the coal bed. At present, principal detection methods include remote sensing, borehole temperature measurements, and geochemical and geophysical measurements.
TIR is a remote sensing method that detects variations in heat on Earth’s surface34. The use of airborne TIR for mapping and studying coal fires has greater resolution and availability than satellite TIR imagery. Recent advances in UAVs equipped with global positioning systems and digital cameras are reducing the cost of collecting imagery. High-resolution thermal cameras have been successfully mounted on aircraft platforms and on UAVs, increasingly using high-performance sensors with smaller size and weight and greater spectral and spatial resolutions. The thermal cameras can reach centimetre-scale ground resolution and provide sufficient accuracy.
TIR Zenmuse XT2 cameras mounted onto a UAV DJI M210 were used to acquire data. The Zenmuse XT2 gimbal and cameras, which included a forward looking infrared detector and a visual camera, provided both infrared and visual images simultaneously. The forward looking infrared camera performed high-sensitivity infrared scanning at 640/30 fps
Airborne TIR technology has a wide detection range and high image resolution, which provides great spatial detail for mapping coal, especially based on UAVs. Thermal anomalies induced by underground coal fires can be extracted from TIR data using an exclusion method, together with field temperature measurements. TIR data are widely used to delineate subtle surface thermal anomalies associated with underground coal fires.
Posted By : Yogender Pancholi on Wed, 26 Aug 2020