Share Email Print
cover

Proceedings Paper

Polarization and ring effect influences upon stratospheric DOAS measurements
Author(s): Ivan K. Kostadinov; Giorgio Giovanelli; Fabrizio Ravegnani; Franco Evangelisti; Paolo Bonasoni; Rolf Werner; U. Bonafe
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

The problems of the stratospheric ozone decline during the last decades is the subject of scientific efforts to discover the main factors influencing the processes leading to its disappearance. The exact understanding of chemical- physical processes in the Earth's atmosphere needs high- quality representative measurements for time-series and modeling study. The present paper deals with the problems of the polarization characteristics of DOAS instruments and the corresponding requirements for instrumental orientation relative to the scattered plane. To avoid the polarization effects upon the measurement's accuracy the instrument has to be 'unpolarized'. A fiber optic and an appropriate diffraction grating are used to do this. Experimental measurements have been carried out to check the possibility to use a fiber optic bundle for DOAS applications. The results obtained from this experiments how that the tested fiber bundles do not completely destroy the polarization state of the incoming radiation. At the fiber exit the degree of the polarization reaches up to 10-15 percent in the measured spectral intervals. On the other hand, accordingly to some of the existing methods, to remove Ring effect from the measured zenith spectra, the DOAS instrument used has to be strongly 'polarized'. This achieved by means of a polarizer inserted into the instrument. The assumption is that, applying such kind of measurements makes it possible to separate the Rayleigh from the Raman scattering. The latter e is assumed as unpolarized, which is in conflict with the theory. A new method base on the deconvolution is offered by use as a possible way of overcoming the problems with the Ring effect.

Paper Details

Date Published: 22 May 1997
PDF: 10 pages
Proc. SPIE 3106, Spectroscopic Atmospheric Monitoring Techniques, (22 May 1997); doi: 10.1117/12.274706
Show Author Affiliations
Ivan K. Kostadinov, STIL (Bulgaria)
Istituto per lo Studio dei Fenomeni Fisici e Chimici della Bassa ed Alta Atmosfera (Italy)
Giorgio Giovanelli, Istituto per lo Studio dei Fenomeni Fisici e Chimici della Bassa ed Alta Atmosfera (Italy)
Fabrizio Ravegnani, Istituto per lo Studio dei Fenomeni Fisici e Chimici della Bassa ed Alta Atmosfera (Italy)
Franco Evangelisti, Istituto per lo Studio dei Fenomeni Fisici e Chimici della Bassa ed Alta Atmosfera (Italy)
Paolo Bonasoni, Istituto per lo Studio dei Fenomeni Fisici e Chimici della Bassa ed Alta Atmosfera (Italy)
Rolf Werner, STIL (Bulgaria)
U. Bonafe, Istituto per lo Studio dei Fenomeni Fisici e Chimici della Bassa ed Alta Atmosfera (Italy)


Published in SPIE Proceedings Vol. 3106:
Spectroscopic Atmospheric Monitoring Techniques

© SPIE. Terms of Use
Back to Top