The IRSOL data archive includes now a new entry: the Atlas of the Third Solar Spectrum and its Center to Limb Variation.
The spectroscopic data were obtained from an observing project at the IRSOL Gregory-Coudé telescope that lasted few years. The involved authors were M. Setzer, R. Ramelli, M. Engelhard, M.Bianda, F. Paglia, J.O. Stenflo, G. Küveler and R. Plewe.
The atlas of the Third Solar Spectrum (SS3) represents the ratio between the intensity spectrum at different distances from the solar limb and the intensity spectrum at disk center (µ = 1.0), both in units of the intensity of the local continuum level. The observing positions of the measurements cover 9 different µ values along the solar axis ranging from 0.1 to 0.9 in step of 0.1, where µ=cosθ is the cosinus of the heliocentric angle θ. The current version of the atlas covers the wavelength range from 4384Å to 6610Å.
The atlas can be found at the URL:
http://www.irsol.usi.ch/data-archive/clv-ss3/