Document - Technical Note
After 11 years of GOME measurements, with the instrument still in good shape, ESA has decided on the first complete Level 0-to-1 processing of the entire GOME data set. The main driver for this reprocessing has been the gaps in GDP solar calibration spectra over long time periods, caused by pointing issues on the ERS-2 platform. The new GDP contains improved limit checking on solar spectra, improved line selection for better spectral calibration stability, and algorithmic changes described in this document. The precision error on the solar spectrum has been reformulated, and severaloptions have been updated in the GDP extraction software, following the CHEOPS-GOME study. This comprises improved Peltier crosstalk correction in Band 1a, seasonal correction on BSDF, improvement in Polarisation Correction, and a new degradation correction of Earthshine Reflectivity. As for the Fifth Issue, we maintained the older algorithm descriptions and added the new ones to the end of each chapter.