Alignment of the ATLAS inner detector tracking system

The inner detector tracking system of the ATLAS experiment comprises different complementary technologies for tracking purposes: silicon and straw tubes gaseous detectors. In order to reach the optimal performance of the tracker, a high-precision alignment of the detecting elements is required. Several track-based alignment algorithms have been developed for the inner detector. The principles of the different methods and real data results from the ATLAS 2008 cosmic ray run are reported.