Software Systems
The overview diagram below illustrates how the different systems interact with the primary processes behind the observatory’s science operations: the submission, execution and return of processed data associated with a scientific proposal.
ACADA – Array Control and Data Acquisition System
The ACADA encompasses all of the software responsible for the supervision and control of telescopes and calibration instruments at both CTA array sites, including the efficient execution of scheduled and dynamically triggered observation. The system will manage the data acquisition and compression of the raw data, as well as the generation of automatic science alerts. The ACADA also provides the user interface for the site operators and astronomers. Its sub-systems are as follows:
- Resource Manager and Central Control
- Human Machine Interface
- Array Data Handler
- Science Alert Generation Pipeline
- Short-Term Scheduler
- Transients Handler
- Monitoring and Logging Systems
- Array Alarm System
- Array Configuration System
- Reporting System
DPPS – Data Processing and Preservation System
The main purpose of the DPPS is to transform raw data products generated by ACADA into low-level science data products appropriate for science analysis, which are delivered to the SUSS for dissemination. It must ensure that all data products are preserved (replicated to at least two off-site data centres), of traceable and reproducible provenance and of the highest scientific quality. The latter is achieved by planning for the periodic re-processing of all data using updated techniques. The DPPS also provides continuous monitoring and quality reporting for its sub-systems and produces high-level science quality metrics and reports related to the services provided. Finally, the DPPS system provides the user interface to all of its sub-systems for specialists, such as the site operators and site astronomers. The DPPS will be implemented as a distributed system, deployed as a set of Data Processing and Preservation Nodes, which will run at the CTA-North and CTA-South data centres, on three CTA off-site data centres and at the SDMC Data Centre. The DPPS sub-systems are as follows:
- Operations Management System
- Computing Workload Management System
- Bulk Archive and File Transfer Management System
- Data Processing Pipeline System
- Calibration Production Pipeline System
- Data Quality Pipeline System
- Simulation Production Pipeline System
- Common Software Frameworks
SUSS and SOSS – Science User Support System and Science Operations Support System
The SUSS manages the software system for the high-level science operations workflows, from proposals to data delivery and user support, and is the main access point for the exchange of science-related products with the science users. It also provides the software for the observation planning with long-term to mid-term schedules, for the automatic generation and verification of high-level science data products, the Science Archive, the Science Analysis Tools and the Science Portal through which the software applications, services, data and software products are accessible. The SUSS sub-systems are as follows:
- Proposal Handling
- Long-Term and Mid-Term Scheduling
- Automatic Data Product Preparation and Verification
- Science Analysis Tools
- Science Archive
- Science Portal
- Help Desk and User Support
- Reporting/Diagnosis
The SOSS is a collection of software tools that support the systems involved in science operations workflows, such as ACADA, DPPS and SUSS. It allows the respective systems to access and share science operations-related information and configurations. It includes the means to track the state of the proposals and observations throughout their life cycle and the state of the CTA Observatory throughout the science operations workflow and science performance.