The doctoral thesis from one of us researchers led to a cover article in the journal published by the Optical Society of America.
“Flame- spectra temperature estimation based on a color imaging camera and a spectral reconstruction technique” is the name of the cover article in the October 2014 issue of the US journal Applied Optics (volume 53). The text is an inspiration of “Development of Multispectral Acquisition Systems for Monitoring and Characterization of Industrial Process”, a work by Cefop’s researchers in Universidad de Concepción.
The investigation time was three years, under the eaves of a FONDECYT project, led by professor of this thesis, Dr. Luis Arias, an academic researcher from the Faculty of Engineering in the University. The project proposes a system that retrieves flames spectra and their temperature estimates based on color images of the same. A spectral resolution of ~ 0.4 nm is achieved with an optical system comprised of a color camera, a linear model, spectral data training a flame and a spectral reconstruction procedure.
To test this concept, the recovered local spectra are compared with measurements made with a commercial spectrometer. In order to estimate the absolute temperature maps flame two radiometric images in different wavelengths are reconstructed and method of two-color pyrometry applied. Experiments show errors of about 2.0% to estimate temperature, which makes this system a tool for determining spatial flame temperature in the combustion process monitoring practice.
“The aim of this work was to estimate multi-spectral information mainly from flames in the combustion process and, from that, to estimate the spatial distribution of temperature”, said Dr. Carlos Toro, researcher from CEFOP that reached his degree of Doctor of Engineering Science with a major in Electrical Engineering from the University of Concepción, thanks to this research.
For his part, Dr. Luis Arias valued the importance of the results. “The contribution of the work of Carlos has been to improve the process of recovering spectral or colorimetric, using the Maloney-Wandell technique, considering different channel gains. This allows to use any commercial color camera for spectral recovery process, previous to the characterization of these gains”, said the professor.
The researcher Carlos Toro also was co-directed by Dr. Sergio Torres, also a professor in the Faculty of Engineering and member from Cefop. “The future potential of the developed technique, when applied in the far and middle infrared bands, is the ability to achieve hyper spectral resolutions of nanometers. Certainly, this will be a significant contribution”, said.
In addition, Professor Torres valued the fact that this research, thanks to a dynamic collaborative work between researchers from different generations, enriches the experience of young researchers in their works. “I’m glad with the selection of this work for the cover of this prestigious journal in our specialty, because it will give worldwide exposure on the subject to our University of Concepción, the Center for Optics and Photonics, CEFOP, and the Department of Electrical Engineering”, said the professor.