CMS Silicon Strip alignment and monitoring with the Laser Alignment System

The alignment of the CMS Silicon Strip detector can be monitored using its built-in Laser Alignment System. The 32 Laser beams in endcaps and the eight Laser beams connecting the barrel and the endcap regions make it possible to monitor the alignment changes to a precision better than 10 μ m and the measurement of the absolute alignment parameters better than 100 μ m . is, 434 of the Silicon Strip modules (3%) are illuminated by the Laser beams, assuring a continuous surveillance during the collisions and cosmics data taking. In this contribution the status and the preliminary results of monitoring and alignment parameters during the 2011 data taking period at the Large Hadron Collider (LHC) are presented.