Determination of Firebrand Characteristics Using Thermal Videos

Abstract

Burning firebrands generated by wildland or prescribed fires may lead to the initiation of spot fires and fire escapes. At the present time, there are no methods that provide information on the thermal characteristics and number of such firebrands with high spatial and temporal resolution. A number of algorithms have been developed to detect and track firebrands in field conditions in our previous study; however, each holds particular disadvantages. This work is devoted to the development of new algorithms and their testing and, as such, several laboratory experiments were conducted. Wood pellets, bark, and twigs of pine were used to generate firebrands. An infrared camera (JADE J530SB) was used to obtain the necessary thermal video files. The thermograms were then processed to create an annotated IR video database that was used to test both the detector and the tracker. Following these studies, the analysis showed that the Difference of Gaussians detection algorithm and the Hungarian tracking algorithm upheld the highest level of accuracy and were the easiest to implement. The study also indicated that further development of detection and tracking algorithms using the current approach will not significantly improve their accuracy. As such, convolutional neural networks hold high potential to be used as an alternative approach.

The world is burning: What exactly are firebrands and why should anyone care?

“…Other studies have been undertaken to image firebrands using firebrand generators. For work done at Tomsk State University in Russia, a study was devoted to the development of new algorithms and their testing and, as such, several laboratory experiments were conducted (Prohanov et al, 2020). Wood pellets, bark, and twigs of pine were used to generate firebrands.…”

Fine-Scale Fire Spread in Pine Straw

“…They manually determined the flaming front locations of each image and the displacement vectors between consecutive images. Prohanov et al [13] developed algorithms to detect and track firebrands. They also provide errors, but they do not provide statistical distributions of their data.…”