Engineering & Technology Development

Engineering and technology development is a key pillar in SARAO’s vision to provide technical and scientific solutions to astronomy and associated disciplines. With close to 1,000 person-years of astronomy engineering experience gained through the design and construction of MeerKAT, SARAO, in collaboration with local universities and industry, has significant participation in external projects such as SKA Mid, the ngVLA, the SALT optical telescope upgrade and guest instruments.

SARAO is committed to the development of radio astronomy infrastructure and capacity on the African continent, specifically through its VLBI program.

This expertise is not limited to astronomy: SARAO was called upon to manage the National Ventilator Project – South Africa’s strategic response to the COVID-19 pandemic, during which 20,000 CPAP ventilators were designed, manufactured and deployed.

The engineering competencies that SARAO has developed through the MeerKAT project and its long-term operation of HartRAO cover all technologies and techniques associated with modern radio telescopes and allied instruments. Local industry and universities provide specialist support to SARAO through contracts, collaboration agreements, and the Human Capital Development program. These competencies are summarised below.

Science Data Processing (SDP)

Through various mechanisms, SARAO manages collaborations with partner institutions to produce data processing pipelines and develop new algorithms and tools for radio astronomy science data processing, specifically interferometric calibration and imaging. Participants in these collaborations include the internal SDP and Radio Astronomy Research Group (RARG), local university research groups (through the HCD program) and other radio observatories and institutions. These collaborations have added significant scientific value to MeerKAT and other telescopes, providing high-quality imaging data products by applying cutting-edge calibration and imaging techniques.

Antenna Optics and Receivers

In line with its systems engineering approach, SARAO treats radio telescope receptors as a system that includes all aspects of the signal paths, from sky to digital signal. In conjunction with EMSS Antennas, the MeerKAT reflector optics and feeds were designed as a combined system to ensure optimal performance in terms of sensitivity and primary beam characteristics. This experience was refined and applied to the SKAmid receptors by the same team. The MeerKAT cryogenic receivers represent the pinnacle of high-performance, broadband single-pixel receptors, again designed with a systems engineering approach that focused on the critical requirements derived from the science objectives.

Digital signal processing

The MeerKAT correlator is based on the CASPER architecture that uses a combination of commodity and bespoke components to provide the required functionality for the central digital signal processor (or correlator/beamformer). SARAO has played a leading role in the international CASPER collaboration, providing hardware, firmware and software solutions. The processing elements in the current MeerKAT correlator are field programmable gate arrays (FPGAs), the technology that was most appropriate at the time of the design. A new correlator is currently under development for the MeerKAT extension project that is based on graphical processing units (GPUs), illustrating SARAO’s agile approach to tracking appropriate technology solutions.

Systems engineering

A systems engineering philosophy and methodology underpins all aspects of engineering projects undertaken by SARAO. SARAO introduced the advantages of applying this methodology to large projects to the radio astronomy community, and the success of the MeerKAT project in delivering a product on schedule, on budget and above specification has ensured that this approach has been adopted by other large astronomy projects, including the SKA and ngVLA. Through staff transfers and collaboration agreements, SARAO systems engineers are playing a vital role in the SKA project.

Digitisation

One of SARAO’s innovative engineering achievements for MeerKAT was the direct digitisation of radio frequency signals at the output of the feed/receiver subsystem - a significant departure from the traditional heterodyne systems employed on most existing radio telescopes. The design and manufacture of the MeerKAT digitizers overcame a range of engineering challenges to deliver a product that archives the scientific requirements of dynamic range, gain and phase stability, timing precision and electromagnetic interference (EMI) suppression. SARAO has completed a licence agreement with Wideband Receiver Solutions, which resulted in the commercialisation of the MeerKAT digitiser and other associated receiver technology ready for deployment within the defence, telecommunication and space sectors. SARAO is currently developing next-generation, high-bandwidth digitiser technologies for astronomy and broader applications.

Mechanical Team – What we do

The mechanical team is responsible for the design and implementation of mechanical and mechatronic systems related to radio telescopes and associated instrumentation. The team has a broad range of competencies, including CAD and product data management, Structural Analysis (FEA, Static, dynamic, fatigue), Computational Fluid Analysis (CFD) and Thermal Analysis. The services provided by the team include product development, the generation of configured production data packs, qualification testing, quality investigation and service failure investigations (root-cause analysis). They have specialist experience in the requirements of radio astronomy, including mechanical design for EMI performance.

Radio Frequency Interference (RFI)

The SARAO RFI team ensures the continued protection of radio astronomy assets from radio frequency interference. The key areas of expertise are the design of EMI-compliant devices, RFI compliance testing and qualification of telescope components, the design, deployment and operation of RFI monitoring infrastructures, the management of RFI at telescope sites, and spectrum management. The RFI team interacts closely with other engineering teams where domain knowledge transfer is required. The team are playing a critical role in the SKA-mid project, particularly in the RFI qualification of the dish structure and management of the RFI consequences of on-site construction activities. SARAO, working with national administrations and other key international stakeholders within the global radio astronomy community, drove the development of a successful African Telecommunications Union proposal to consider the impact of...

Software

The software group plays an indispensable role in ensuring the smooth operation of the MeerKAT telescope, and they contribute to SKAO software development through the provision of developer teams in the SAFe environment. They have expertise in all aspects of telescope operation, from proposal management and UI/UX to implementing dynamic schedulers and lowlevel communication protocols. Their proficiency in Data Storage Solutions has been crucial for efficiently managing the vast amounts of data generated by MeerKAT, ensuring secure storage and facilitating easy access to archived data for future analysis and comparison.