Observation of the solar spectral irradiance from 200 nm to 870 nm during the ATLAS 1 and ATLAS 2 missions by the SOLSPEC spectrometer

Abstract

The SOLSPEC instrument was built to measure the solar spectral irradiance from 200 nm to 3000 nm. The instrument participated in the three ATLAS missions. It consists of three spectrometers, which measure the solar spectral irradiance in the ultraviolet, visible and infrared domains. The ultraviolet and visible solar spectra obtained during the ATLAS 1 mission have been presented elsewhere. Measurements during the second flight are presented in this paper. Most of the ATLAS 1 results are confirmed by the ATLAS 2 measurements, but some improvements are obtained in certain wavelength domains owing to better calibration procedures and selection of measurements. The data gathered during the first two flights by the SSBUV, SUSIM and SOLSPEC spectrometers are compared and discussed.