Level 1 reference irradiance files provide solar irradiance measured using the reference solar diffuser. Each file includes the measured solar irradiance for all the North-South cross-track pixels. The files are provided in netCDF4 format, and contain information on radiometrically and wavelength calibrated solar irradiance for the UV and visible bands, corresponding noise, parameterized wavelength grid, solar viewing geometry, quality flags and other ancillary information. The product is produced using the L0-1b processor which includes multiple steps: (1) Image processing to produce radiometrically calibrated radiance, and (2) Additional wavelength calibration to improve wavelength registration. These data reached provisional validation on December 9, 2024.