Alignment of the ATLAS Inner Detector

The performance of the ATLAS Inner Detector (ID) is crucially dependent on how accurately one can determine the position and orientation of the thousands of detector modules that it is comprised of. In order not to degrade performance significantly, module positions must be known to O(10µm) precision. Here we describe the track-based alignment algorithms used to provide alignment at this level and how they are implemented within the ATLAS data taking framework. We present results of alignment tests on simulated data, the results of aligning with the first cosmic ray events taken with the full ID, and some of the systematic problems that can arise with track-based alignment approaches.