Synoptic maps from two viewpoints - Preparing for maps from SDO/HMI and SO/PHI data P. Loeschl, J. Hirzberger, S. K. Solanki, J. Schou and G. Valori A&A, 682 (2024) A108 Published online: 08 February 2024 DOI: 10.1051/0004-6361/202346044