COMPARING GROUND-LEVEL SPECTRALLY RESOLVED SOLAR UV MEASUREMENTS USING VARIOUS INSTRUMENTS - A TECHNIQUE RESOLVING EFFECTS OF WAVELENGTH SHIFT AND SLIT WIDTH
H. Slaper et al., COMPARING GROUND-LEVEL SPECTRALLY RESOLVED SOLAR UV MEASUREMENTS USING VARIOUS INSTRUMENTS - A TECHNIQUE RESOLVING EFFECTS OF WAVELENGTH SHIFT AND SLIT WIDTH, Geophysical research letters, 22(20), 1995, pp. 2721-2724
Spectrally resolved UV measurements are important for the study of bio
logically relevant UV in relation to changes in atmospheric parameters
. The inter-comparison of spectral instruments is essential as measure
ment techniques and calibrations are not standardized. The differences
in slit functions cause large spectral variations when comparing the
spectral readings directly. The method described, which compares spect
ral readings using different instruments, corrects for differences of
wavelength calibrations and slit functions, and does not require knowl
edge of additional atmospheric parameters and UV-transfer model calcul
ations. The wavelength alignment has an accuracy of 0.02 nm over the w
avelength interval from 300-400 nm, and a reproducibility of 0.01 nm.
The robustness of the methods and reproducibility of results are shown
in the evaluation of a seven day intercomparison campaign with three
different scanning spectroradiometers.