Alignment of the ATLAS Inner Detector

In order to reach the track parameter accuracy motivated by the physics goals of the experiment, the ATLAS tracking system needs to determine accurately its almost 700,000 degrees of freedom. The demanded precision for the alignment of the silicon sensors is below 10 μm. The implementation of the track based alignment within the ATLAS software framework unifies different alignment approaches and allows the alignment of all tracking subsystems together. The alignment software relies on the tracking information (track-hit residuals) but also includes the capability to set constraints on the beam-spot and primary vertex as well as the momentum measured by the Muon System or the E/p using the calorimetry information. The alignment result of the ATLAS tracker using the 2011 collision data will also be presented.