Initial radiometric calibration of the High-Resolution EUV Imager (${\text{HRI}}_{\text{EUV}}$) of the Extreme Ultraviolet Imager (EUI) instrument onboard Solar Orbiter

S. Gissot, F. Auchère, D. Berghmans +21

The ${\text{HRI}}_{\text{EUV}}$ telescope was calibrated on ground at the Physikalisch-Technische Bundesanstalt (PTB), Germany's national metrology institute, using the Metrology L…