Abstract

Measurements of the optical thicknesses produced by particulate matter extinction and nitrogen dioxide absorption at window wavelengths in the visible and near-infrared spectral range were taken with four examples of a multiwavelength sun photometer. Evaluations of the vertical content of nitrogen dioxide were made by examining these measurements with a procedure which attempts to separate gaseous absorption from particulate extinction, represented in terms of Ångström’s formula. Moreover, assuming that the vertical content of NO₂ and Ångström’s turbidity parameters are given by the average values calculated with this procedure, we obtained a set of useful correction factors for the monochromatic calibration values of the four sun photometers.

© 1985 Optical Society of America

Multiwavelength sun-photometers for accurate measurements of atmospheric extinction in the visible and near-IR spectral range

Claudio Tomasi, Franco Prodi, Monica Sentimenti, and Giulio Cesari
Appl. Opt. 22(4) 622-630 (1983)

Comparison of Sun photometer calibration by use of the Langley technique and the standard lamp

Beat Schmid and Christoph Wehrli
Appl. Opt. 34(21) 4500-4512 (1995)

General method for calibrating Sun photometers

Bruce W. Forgan
Appl. Opt. 33(21) 4841-4850 (1994)

Direct solar radiation: spectrum and irradiance derived from sun-photometer measurements

Wolfram Wobrock and Reiner Eiden
Appl. Opt. 27(11) 2253-2260 (1988)

Evaluation of the applicability of solar and lamp radiometric calibrations of a precision sun photometer operating between 300 and 1025 nm

Beat Schmid, Paul R. Spyak, Stuart F. Biggar, Christoph Wehrli, Jörg Sekler, Thomas Ingold, Christian Mätzler, and Niklaus Kämpfer
Appl. Opt. 37(18) 3923-3941 (1998)