Pre-alignment of CLIC using the double-wire method

The pre-alignment and active control method for the Compact Linear Collider (CLIC) is described. Two new types of instruments are used in this system-a biaxial Wire Positioning System (WPS) which uses a stretched wire as the spatial reference, and a capacitive three axes Tilt Meter System (TMS). The instruments, and the way they are used with the well-known Hydrostatic Levelling System (HLS) are described.