The project “3D Fire Laboratory” (3DFIRELAB) is a study on field scale forest fire radiative transfer. The project aims at developing monitoring methodology and modelling tools to better understand the limitation of Infra-Red (IR) fire imagery and improve their use in operational product such that fire front monitoring or fire emission estimation.
The project action lies between the two fire science communities of (i) combustion which has interest in upscaling effect of smaller flame scale fire dynamics to field scale front and (ii) atmospheric remote sensing which relies in part on empirical relationship and IR images to compute satellite product and model fire atmospheric disturbance.
One option to monitor fire at global scale is based on the Fire Radiative Power (FRP), a satellite active fire product. It is a measure of the instantaneous total energy released by the fire. It was shown on small scale experimental fire (~1m) to have a linear relationship with vegetation mass consumption. This made it very appealing to estimate global fire emission in real time. Furthermore, one of its formulation is only based on the measure of one single spectral band, making it easy to compute.
The objective of the project is to create a simulation tool that can model radiative transfer in a fire scene at a scale more relevant to satellite scale that is small experimental fire. Targeting field scale fire (~100m), two approaches are considered either only simulating the radiative transfer of an observed experimental fire and assessing the impact of IR camera viewing geometry, or setting up a standalone system than can model both the fire dynamics and IR images. The second approach, much more complex, has the potential to give better understanding of energy transfer in fire scene and implication in the FRP estimation.
Overall conclusions of 3DFIRELAB actions:
- The project was the opportunity to develop a system that can create connection between fire science communities, providing a methodology applicable to field scale simulated fire that can simulate IR images, a direct observable from experimental fire. The different fire (FDS, ForeFire), atmospheric (MesoNH) and radiative transfer (DART) models used in the project were in most of the cases pushed outside their zone of normal utilization. This fueled a lot of theoretical discussions to understand the validity of the result, in particular in the validation of DART. The scientific results of the project were disseminated both among the international and European fire science community, through written articles and oral presentations as well as the organization of a workshop.
- a 3DFireLab creation is also the development of a methodology and image processing algorithms that can extract the essential fire behavior metrics out of imagery from IR airborne handheld camera. Tasks of image orthorectification and fire front segmentation were automatized to process more that 3000 images collected during 4 burns of several hectares conducted in savannah type vegetation. The algorithms and the data are in the process to be published in open source.
- Finally the project provided training to the researcher in various ways (networking capacities, professional and management skills), helping his career prospects in the academia and beyond.
