Intercomparison of reflectances observed by GOME and SCIAMACHY in the visible wavelength range.

We compare the Earth reflectances of the spectrometers Global Ozone Monitoring Experiment (GOME) and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) over their overlapping wavelength range (240-800 nm). The goal is to investigate the quality of the radiometric calibration of SCIAMACHY using calibrated GOME data as a reference. However, severe degradation of the GOME instrument in the UV since 2001 prevents it from being a reliable reference below 500 nm.

Prelaunch characterization of the Ozone Monitoring Instrument transfer function in the spectral domain.

A method and an experimental measurement setup to accurately characterize the instrument transfer function in the spectral domain for hyperspectral spectrometers in the ultraviolet-visible wavelength range are described. The application to the on-ground calibration of the Ozone Monitoring Instrument (OMI) on board the Earth Observing System Aura satellite is presented and discussed. With this method and setup, based on an echelle grating, a sampling of the instrument transfer function in the spectral domain can be selected and is not limited by the spectral resolution and sampling of the spectrometer that is being characterized.