The goal is to formalize the methodology from determining atmospheric
extinction using the multi-filter channel of SNIFS. This formalism must
then be tested with Monte Carlo techniques, simulating the numbers of
stars and their expected fluxes in the various bandpasses of the
multi-filter channel along with variability in atmospheric parameters.
The document "Flux calibration requirements" and "Extinction monitoring
with LRF" on the main SNfactory page can serve as starting points.