GOME Level 1 products contain Earthshine radiance at the Top of the Atmosphere and solar irradiance spectra. They were generated by DLR on behalf of the European Space Agency with Level 1 GOME Data Processor (GDP-L1) starting from the Extracted GOME Calibration (EGOC) Level 0 data files.
Originally raw detector signals (binary Analog to Digital Converted units) of the science measurements plus calibration constants were provided (dataset version 4 and lower), but following the end of the operational phase of the ERS-2 mission (2 July 2011), as part of ESA's post-operational algorithm improvement activities (Coldewey-Egbers et al., 2018), the GOME Level 1 data type was entirely revised and a dataset of fully calibrated and ready to use data was generated with GOME processor version 5.1. The version 5.1 data bring relevant quality improvements for the revised calibration approach, compensating aging and instrument degradation, and provide enhanced accessibility.
The version 5.1 data are in NetCDF format and differ fundamentally from the previous GOME Level 1 data, having the Envisat proprietary format and basically containing Level 1a data where a dedicated extraction software tool had to be applied by end user to obtain spectrally and radiometrically calibrated radiances (including the correction for polarisation, leakage current and stray light). Such calibrations are now applied to the version 5.1 L1b data product in the standard processing.
Users of GOME Level 1 products are strongly recommended to migrate to the latest reprocessed dataset. Please consult the GOME Product Quality Readme file before using the data.