Calibration and early results of MERIS on ENVISAT

ENVISAT, ESA´s ENVIronmental research SATellite, was launched on 1 March 2002. The MEdium Resolution Imaging Spectrometer MERIS is responding nominally. The launch of ENVISAT signals the go-ahead for a nine-month commissioning phase for instrument calibration, algorithm verification and initial validation of geophysical data products. The first six months will be dedicated to the inflight verification and radiometric and spectral characterisation of the instrument. During that phase verification of the algorithms and data products will also be initiated, with the emphasis shifting progressively to the validation of geophysical products. Due to time constraints the only results available at this early stage will be the early in-orbit instrument health and functionality checks; the coarse calibration results, the spectral in-flight characterisation results as well as the preliminary optimisation of MERIS mission operational parameters.This paper describes the initial steps of the MERIS commissioning phase and presents the first available results.