The Cherenkov Telescope Array Observatory (CTAO) would not work without software, powerful computers and vast amounts of storage required to combine and process what the individual telescopes capture into usable scientific results. The challenge faced by the CTAO Computing Department is to design and implement a system that supports everything from accepting observation proposals to scheduling observations, controlling the telescopes, processing and archiving the data at all levels and disseminating data products and science tools to the public using open standards and FAIR (findability, accessibility, interoperability, and reusability) principles.
Because such a computing system does not exist as a stand-alone product, the work of the Computing Department covers all steps from architectural design to construction, validation, deployment and maintenance. The technical challenges and long lifetime of the Observatory will necessitate the development and adoption of new techniques and technologies to meet the scientific demands. Even when built, long-term maintenance will not be simple: the software and hardware systems will need to be operated over the thirty-year lifetime of the Observatory, and the science data archive will continue to be operated for a further ten years after that. This means software systems engineering activities are as important as the code itself.
Since much of the software will be developed by diverse and dispersed teams from the CTAO’s institution and industrial partners, this requires the coordination and release of a wide range of in-kind, in-house and externally developed contributions. With the fundamental principle of “Several Sites – One Observatory,” the software will not be specific to a particular site but will form a series of distributed and centrally coordinated systems.
The Computing Department will coordinate with several off-site data centre partners for its data processing and simulation needs and is directly responsible for the installation of the on-site data centres and control rooms at the two array sites. It will manage these activities centrally from the Science Data Management Centre (SDMC), which will be located in a new building complex on the DESY campus in Zeuthen, just outside Berlin.