  The muon spectrometer of the ATLAS experiment is one of the largest detectors
ever built. At the LHC, new physics signs could appear through high momentun
muons (1 TeV). Identification and precise momentum measurement of such muons
are two of the main challenges of the ATLAS muon spectrometer. In order to get
a good resolution for high energy muons (i.e. 10% at 1 TeV), the accuracy on
the alignment of precision chambers must be of the order of 50 microns. Several
procedures have been developed to reach such a precision. This document
describes complementary techniques used to align the muon sub-detectors, and
their results : the optical system, the muon cosmic rays and the straight
tracks coming from collisions.
