Light field imaging analysis of flame radiative properties based on Monte Carlo method

Light field imaging, which is one of the noncontact flame measurement methods, can capture and record multiangle radiative intensity information of a flame through a single shot. After the postprocessing and integration of the flame information, the three-dimensional reconstruction of the temperature and radiative properties can be achieved. However, the diversity and universality of the reconstruction parameters make the reconstruction process complex and redundant. Therefore, the order of priority in which the radiative properties (attenuation coefficient, scattering albedo, and scattering phase function) of a flame influence light field imaging should be analyzed by simulation. This study aims to simplify the reconstruction process by simulating the light field imaging of nonuniform temperature distribution using a previously developed multifocus plenoptic camera model. In addition, a quality evaluation system is established to quantitatively analyze the optical influence of different radiative properties in the flame medium on the light field imaging process. The following conclusions are drawn by analyzing the aperture image of the flame with different radiative properties: (1) The attenuation coefficient should be the first priority for the reconstruction of the radiative characteristic parameters of the flame. (2) The scattering albedo should be the next consideration for ensuring high reconstruction precision. (3) For the scattering phase function, the only consideration is whether it is more affected by either isotropy or anisotropy.