Data Processing Pipeline of the SUTRI EUV Imager on the SATech-01 Satellite

Solar observations in extreme ultraviolet (EUV) wavelengths are a crucial component of solar activity research and space weather forecasting. The Solar Upper Transition Region Imager (SUTRI) on the SATech-01 satellite is designed to take full-disk solar images in the Ne vii 46.5 nm spectral line (T = 0.5 MK). It was launched in 2022 and the science data were released on January 10, 2023. In this article, we describe the data preprocessing method employed to SUTRI data to eliminate inherent instrument effects and standardize the raw data to obtain scientific data. Alongside common data processing steps, our pipeline includes correcting for horizontal stripes from the CMOS imaging camera. As an experiment payload, SUTRI does not have an image stabilization system. Thus, a multi-step iterative algorithm has been developed to precisely align series of drifted images due to the limited pointing accuracy of the satellite platform. Our method may not be limited to SUTRI; it also serves as a reference for future solar EUV telescope data processing.