In order for fiber-fed spectroscopic instruments on large telescopes to live up to their full potential, both innovative hardware and advanced software techniques must be developed so that appropriate levels of sky subtraction can be realized. Fiber Optic Characterization for Unprecedented Sky Subtraction (FOCUSS) is a recently funded (NSF Grant 2009430) project to develop the techniques, software, and hardware required to characterize fiber optics in order to remove the influence of changing focal ratio degradation, transmission, defocus and other effects over many fibers, and during a years long spectroscopic survey. This will ensure that spectra taken at different times, air masses, through different fibers, etc. will be comparable.
This project is ongoing and the sections below will be updated as progress is made.