Three-dimensional-imaging thermal surfaces of coal fires based on UAV thermal infrared data

Abstract

ABSTRACT The quick and precise location of the burning zones of coal fires, which are continuously burning in abandoned coal mines worldwide, has long been a technical problem. The unmanned aerial vehicle (UAV) can reduce field work intensity, improve data collection efficiency, and ensure high accuracy at low cost. In order to visualize the distribution of burning points of coal fires, the UAV-based thermal infrared oblique photography is adopted. A 4-step 3D thermal imaging method is proposed in which the processing of thermal images is the most crucial. Furthermore, a software program is developed to improve the contrast and quality of batches of thermal images in one-click as well as to unify the temperature level and scale in each thermal image. This methodology is implemented in the Maoergou coal fires in China to reconstruct the surface thermal field in genuine 3D. The high-temperature zones are illustrated clearly in the 3D thermal model. The results indicate that this methodology can be used as a tool for the delineation of coal fires and other types of thermal anomaly scenario.