[Novel analysis algorithms for differential optical absorption spectroscopy for pollution monitoring]

Differential optical absorption spectroscopy, or DOAS, is a widely used method to determine concentrations of atmospheric species. The principle of DOAS for measuring the concentration of air pollutants is presented in briefly. Using the linear relationship between the area of the measured differential absorbance curve and that of the differential absorption cross-section curve as taken from the literature, an alternative method for calculating the gas concentration on the basis of the proportionality between differential absorbance and differential absorption cross section of the gas under study was developed. The method can be used on its own for single-component analysis or as a complement to the standard technique in multi-component cases. The procedure can be used with differential absorption cross sections measured in the laboratory or taken from the literature. In addition, the method provides a criterion to discriminate between different species having absorption features in the same wavelength range.