Fine Calibration of Detector Positions by Tracks in Helsinki Silicon Beam Telescope

An efficient algorithm is presented to perform fine calibration of detector positions in a beam telescope. Data from Helsinki Silicon Beam Telescope ( SiBT) are used to demonstrate the performance of the algorithm. The intrinsic alignment precision obtained is better than 1 micrometer in location and about 20 micro-radians in orientation. The algorithm is described in detail and results on performance are presented. Connection to the CMS Tracker alignment problem by tracks is discussed.