We present the pipeline processing (for photometry and spectrophotometry) primarily basedon the comparison of the observation with a prediction from the spectral energydistribution and total flux of the source and a set of parameters modelling the instrumentproperties observation-to-observation. Experiments on G white lightcalibration yield residuals well below one mmag for most of the cases, but for extremecolour stars. For blue and red spectra, tests up to now yield residuals significantlysmaller than the observational noise, except for sources with very strong spectralfeatures, which present flux residuals of 2–3% in the spectral lines (atG = 15). Work continues to account for all instrumental effects, to addcomplexity to the instrument model and to improve the processing pipeline.