The New 2018 Version of the Meudon Spectroheliograph
Résumé
Daily full-disk observations of the solar photosphere and chromosphere started at the Meudon Observatory in 1908. After a review of the scientific context and the historical background, we describe the instrumental characteristics and capabilities of the new version operating since 2018. The major change is the systematic recording of full line profiles over the entire solar disk providing 3D data cubes. Spectral and spatial sampling are both improved. Classical 2D images of the Sun at fixed wavelength are still delivered. We summarize the different processing levels of on-line data and briefly review the new scientific perspectives.