Impact of the ATLAS muon spectrometer alignment system on tracking at the CERN H8 testbeam

The ATLAS muon detector is designed to attain precision muon momentum resolution aided by an embedded optical beam network which monitors thermally induced chamber displacements. We report on the ability of this alignment system to provide corrections for track reconstruction. This work is based on sagitta measurements conducted at the CERN H8 2003 test beam.