Berghmans, David ; Antolin, Patrick ; Auchère, Frederic ; Barczynski, Krzysztof ; Aznar Cuadrado, Regina ; Chitta, Lakshmi Pradeep ; Gissot, Samuel ; Harra, Louise ; Janvier, Miho ; Kraaikamp, Emil ; Long, David ; Mierla, Marilena ; Parenti, Susanna ; Rodriguez, Luciano ; Schühle, Udo ; Stegen, Koen ; Verbeeck, Francis ; Zhukov, Andrei ; EUI team, X

Talk presented at 8th Solar Orbiter Workhop on 2022-09-12

Abstract: On March 7 2022 with Solar Orbiter at a distance of 0.50 AU to the Sun and crossing between the Sun and Earth line, the Extreme Ultraviolet Imager (EUI) with its High Resolution Imager in EUV (HRI-EUV, 17.4 nm) created a 25-panel mosaic of raw exposures covering the entire disc of the Sun. Using this dataset we discuss the biggest challenges of calibrating EUI data in general and HRI-EUV data in specific: from dark and flat calibration, artefacts on the detector in the shape of gummy bears, to the difficulties in combining low and high-gain images into high dynamic range combined gain exposures. Finally, we show how the calibrated images were combined into the highest resolution full-disc solar corona image in Extreme ultraviolet light ever. This combined mosaic image was produced in first instance for outreach purposes. However, some science use and multi-instrument cross-calibration can also be anticipated and we will discuss the limitations and opportunities for this.

Keyword(s): Sun ; corona ; EUI
Note: Oral contribution O23 of the conference abstract book