Empirical Correction of Stray Light within the MERIS Oxygen A-Band Channel

Spaceborne spectrometers like the Medium Resolution Imaging Spectrometer (MERIS) on board the Environmental Satellite (Envisat) are widely used for the remote sensing of atmospheric and oceanic properties and make an important contribution to the monitoring of the earth’s atmosphere system. To enable retrievals with high accuracy, the spectral and radiometric properties of the instruments have to be characterized with high precision. One of the main sources of radiometric errors is stray light caused by multiple reflections and scattering at the optical elements within the instruments. If not corrected for properly, the stray light–induced offsets of measured intensity can lead to significant errors in the derived parameters. The effect of stray light is particularly momentous in the case of measurements inside strong absorption bands like the oxygen A band at 0.76 μm or the ρστ absorption band of water vapor around 0.9 μm. For example, the retrieval of surface and cloud-top pressure from MERIS m...