  The CMS silicon tracking system measures the trajectories of charged
particles with a hit resolution of the order of microns in the pixel detector
and tens of microns in the strip detector. One of the most important inputs for
track reconstruction is the precision with which the tracker geometry is known.
Therefore the position, orientation, and curvature of each tracker sensor must
be precisely determined. Changes in the operating conditions can cause
movements in the different substructures and also in the sensors. For
maintaining the targeted precision, frequent corrections are needed, and the
procedure to determine these corrections is commonly referred to as tracker
alignment. Due to accumulated radiation during data taking, the response of the
sensors changes over time. This affects the local reconstruction of pixel hits
and consequently the result of the alignment procedure. In this contribution,
the alignment procedure in CMS is introduced, as well as the dedicated
calibration for the pixel local reconstruction. The effect of the change in the
local reconstruction due to aging of the sensors on the alignment procedure is
discussed.

Instrumentation and Detectors