Behind the scenes of GS: an eye for accuracy

The CERN sites are constantly evolving… with new buildings, extensions, redevelopment and renovation. The team in charge of geographical information in the GS Department measures and records even the smallest changes so that it can provide everyone at CERN with the most up-to-date plans possible.


The “Patrimony” team in the GS-SE-DOP Section is responsible for geographical information and has the job of updating all of the information relating to CERN's property, including the land made available to the Organization by Switzerland (110 hectares) and France (516 hectares), green spaces, buildings, underground structures, underground networks (gas, water, electricity, etc. – for which the "Patrimony” team works closely with numerous other groups and departments), car parks, roads… and much more.

“Our team consists of seven surveyors and GIS specialists, who identify, define, measure, catalogue and pinpoint the location of every item of CERN's property, buildings or otherwise, on the surface or underground," explains Youri Robert, head of the “Patrimony” team. “All of this information is integrated daily into our Geographic Information System (GIS) portal.”

For example, for a new construction, the surveyors are involved in several stages of the project: before work starts, they make a survey of the land as a basis for the project; when work starts, they plot the footprint of the construction; and finally, after work is completed, they carry out final measurements of the new buildings, roads and networks and create floor plans. “To take measurements of the exterior of buildings, of roads, of green spaces, etc., we use a total station and a GPS device,” explains Samuel Zeler, a survey technician. “The GPS device allows measurements to a precision of 1 cm, which ensures that we can perform very high-quality surveys.”

“To map internal structures (offices, underground areas, etc.) we use a distance meter (an electronic distance measuring device),” adds Hansjuergen Knoop, who is also a survey technician. “We are constantly updating nearly 1300 floor plans, which are available to everyone at CERN through the GIS portal.” Soon, 400 plans of CERN's underground installations (accelerator tunnels, experiment caverns, access tunnels, etc.) will be added to the portal, as LS1 has given the "Patrimony" team the opportunity to get underground and complete its catalogue.

“Keeping the catalogue up-to-date is a long-term job," emphasises Youri Robert, "but it's essential for keeping people and equipment safe. In fact, our plans are the basis for the evacuation plans drawn up by the safety services (HSE) and the Fire Brigade also relies on them in the event of an emergency.” In terms of CERN’s facilities, the "Patrimony” team processes almost 400 declarations of intent to start work (Déclaration d’intention de commencement de travaux - DICT) for the non-fenced areas of the CERN site in France each year and must, in some cases, follow the work very carefully to ensure that none of CERN’s underground networks are damaged. Here too, knowing the exact location of these networks is essential.

The first map of the CERN (Meyrin) site, 1954.

To help everyone at CERN in their work, the “Patrimony” team has also made its GIS platform available. This allows users to map facilities relating to their own areas of expertise. Each specialist can integrate and share his or her own information on a regularly updated common plan. This means that it’s possible to search for and find, in the blink of an eye, the location of fire extinguishers, electrical feed boxes, access systems and radiation monitors… and even most of the components of the accelerators!

To find out more about the work of the “Patrimony” team, see the following articles: Down to the nearest centimetre…”, “CERN in detail”, “CERN building numbers: no rhyme and little reason”. 

And don’t forget to download MapCERN, the GS Department's smartphone application! More information here.

by Anaïs Schaeffer