Optical characterization of volcanic ash using diffuse reflection spectroscopy

ABSTRACT The determination of the optical parameters are important for remote sensing and aircraft, in this case allow the difference between a cloud composed solely of water and water plus ash. Therefore, this research is intended to determine the optical properties of the ash four active volcanoes, by studying the spectral resolution reflectance interpreting the results in the approximation of Kubelka - Munk equation through the transfer equation radiative. The results allow classifying these ashes depending on their place of origin. Keywords: Diffuse Reflection Spectroscopy, vol canic ash and optical parameters. 1. INTRODUCTION In the late twentieth century has been of great technological interest to characterize different materials according to different optical properties due to their refractive indices. When you know the index spectral dependence can be modeled or predict what will be the optical behavior of specific devices in terms of how much electromagnetic energy reflected, absorbed and spread. To study the optical properties of non-homogenous materials in which light additionally to be absorbed is dispersed or redistributed also in the medium, one can obtain the characteristics thereof; additionally allow ashes according categorize the behavior of these parameters. Radiative flux models are important to describe the optical properties of the materials. In this study we used the technique of Kubelka - Munk, which engages the diffuse reflection of light, the impinging light beam on the sample is not homogeneous. This technique is described diffuse reflection of different materials and absorbent dispersing electromagnetic energy; this technique is based on taking the diffuse radiation intensities using the technique Diffuse Reflection Spectroscopy (ERD), obtained from the different powder samples of volcanic ash, similarly characterized by their optical properties, in order to estab lish the spectral signature of each of the aerosol which is of great interest in the sensing of said particles. This work was done to volcanic ash from the Puyehue volc ano, Vesuvius, Popocatepetl and Etna, respectively located in Chile, Italy, Mexico and Sicily (Italy).