Accelerator Surveying and Geodetic measurements (ASG)

The ASG (Accelerator Surveying & Geodetic measurements) section is responsible for the geodetic and large-scale metrology measurements as well as the alignment of the accelerator components and their associated beam transfer lines for the whole CERN site. Furthermore, the ASG section is in charge of the acquisition and processing of high accuracy point cloud data defined in the primary CERN reference frame (CCS). The ASG section is also driving the Research and Development to improve alignment techniques and methods to achieve the requirements of future projects.

The ASG responsibilities and activities include :

  • The initial definition of the new beam lines parameters in the primary CERN coordinates system (CCS),
  • Installation, measurement and maintenance of the geodetic infrastructure at the surface and in the accelerator areas, the relationships between these and local reference systems by determining coordinate transformation parameters,
  • Geodetic measurements with specific instrumentation such as gyro-theodolite, astro-geodesy sensors, GNSS and the associated post-processing,
  • The support to the equipment owners for the design of the alignment systems and the positioning methods,
  • The fabrication control, metrology and fiducialisation of the beam line components or prototypes when the classical workshop methods cannot be applied,
  • The expertise in laser tracker measurements application and providing technical advices (hardware and software) or specific solutions to the CERN community,
  • The measurement, alignment and smoothing of the components on the beam lines for the whole CERN site,
  • The geodetic and mathematical processing of survey data in order to supply the SURVEY database with the beam component offsets for CERN users,
  • High accuracy point cloud data acquisition defined in the primary CERN reference frame (CCS) to conduct studies, quality controls and as-built measurements for beam components, accelerator areas and surface buildings,
  • The dynamic and static measurements for geometrical validations or monitoring processes and deformation analysis,
  • The R&D related to all these tasks for the existing and future machines and upgrades.