The Netherlands
In the Netherlands, scientific and technical preparation for the SKA is coordinated by ASTRON, the Netherlands Institute for Radio Astronomy, one of the institutes of the Dutch Research Council (NWO). The Ministry of Education, Culture and Science represents the Netherlands in the SKAO Council.
Brief history of the Netherlands with the SKAO
The Netherlands has been involved in the SKA project since the very beginning in the early 1990s and, in 2011, was a founding member of the SKA Organisation, a precursor to the SKA Observatory in charge of delivering the SKA telescope designs, involving scientists and engineers from around the world. The Dutch contribution to the SKA design phase consisted of:
- Leading the Low Frequency Aperture Array (LFAA) Consortium, which designed the SKA-Low antenna stations. The work included developing the antennas, low noise amplifiers, analogue signal transport, A/D conversion and beamforming stages of the SKA-Low signal chain. ASTRON led the consortium, focusing on project management and system engineering as well as the deployment of the Aperture Array Verification System (AAVS1), a prototype SKA-Low station, at the Murchison Radio Observatory in Western Australia.
- Taking part in the Central Signal Processor (CSP) consortium. The CSP combines the digitised astronomical signals from the SKA antenna stations and dishes. Its output can be used to make images of the sky or the summed data streams (known as beams) can be analysed to search for signals from time variable sources, such as pulsars. ASTRON participated with Auckland University of Technology (New Zealand) in a team led by CSIRO (Australia) in the design of the SKA Low CSP element. ASTRON's contribution consisted of the development of a high performance signal processing board, called Gemini, with associated water cooling to dissipate the considerable amount of heat generated by the electronic components. A Dutch company from the Electronics Manufacturing Services (EMS) sector produced prototype boards, which were used as a development platform for the associated firmware/software.
- Taking part in the SKA Science Data Processor (SDP) consortium. SDP is the final stage of the SKA telescopes processing chain, before transmission to the SKA Regional Centres (SRC), the final interface with the end-users, namely the astronomers. The purpose of the SDP is to take the data streams from the SKA CSP and turn them into science-ready data products. In order to handle the vast amounts of incoming data (several Tb of data per second per instrument), the SDP will be based on a scalable, data-driven architecture that heavily exploits data parallelism. ASTRON contributed to the high level software system engineering, as well as leading the design of the compute hardware.
- Participation in the Assembly, Integration and Verification (AIV) consortium, providing the experience gained in the construction, commissioning and operation of LOFAR.
- Involvement in the Advanced Instrumentation Programme, consisting in developing technologies for future potential use. One of these was the "Mid-Frequency Aperture Array" (MFAA) element, which sought to develop an aperture array system operating at higher frequencies than the LFAA consortium. The consortium developed, prototyped and evaluated various concepts of front-end (antenna) technology. R&D work is continuing in the Netherlands.
The Netherlands also played an active role in the negotiations to form the SKAO as an intergovernmental organisation. that resulted in the SKA Convention. In August 2019, just a few months after the signature of the SKAO Convention in Rome, Italy, the Netherlands was the first country to officially complete its ratification process.
Then Minister Van Engelshoven (Ministry of Education, Culture and Science of the Netherlands) said in 2019: “As part of the SKA project, the Netherlands is contributing to the development of the world's largest radio telescope. With this large number of antennas, the SKA will generate huge amounts of data; one petabit per second, that is more than three times the worldwide internet traffic in 2018. This is groundbreaking! We are investing 30 million Euros in the project, and that investment will generate employment, activity for industry and knowledge for our society. For example in the fields of IT and sustainable energy. The Netherlands will also strengthen its leading position in science worldwide."
Supporting the SKAO
The SKA will generate more data than we have ever processed and analysed before. To make this possible, innovation in hardware, software and expertise is crucial every step of the data chain. It also drives the need for a network of SKA Regional Centres (SRC) that will form the long term science archive and facilitates access to the data - in terms of both computing hardware and software. Work is ongoing to set up a global network of SKA Regional Centres with nodes across the SKAO member states. The Netherlands is actively involved in the design and prototyping effort, building on the experience gained through the LOFAR telescope, and using this as a platform for cross-fertilisation and early testing of SRC concepts. It is envisaged that the Dutch SRC node will be integrated in ASTRON's Science Data Centre and serve the needs of both SKA and LOFAR, as well as providing access to other, relevant, astronomical data archives through the Virtual Observatory.
Investing in the Science Data Centre can be an investment in far more than radio astronomy. The number of disciplines facing big data challenges is growing. Interdisciplinary cooperation and sharing of resources in areas such as archiving and computing, also involving the Dutch academic service providers, is expected to lead to greater efficiency and lower costs. A first step on the way towards interdisciplinary collaboration is taking place in the Horizon 2020 ESCAPE project, which brings together facilities from astronomy, particle physics, astro-particle physics and gravitational waves observatories. ASTRON, Nikhef (the Dutch National Institute for Subatomic Physics) and SURF, the Dutch national e-Infrastructure provider are working together in the 5-year FuSE project (2021-2025) to develop, build and operate a nationwide e-Infrastructure that will serve the Large Hadron Collider (LHC) at CERN, the SKAO and KM3NeT (a neutrino astrophysics facility under construction in the Mediterranean).
Science drivers
The Netherlands has been playing a critical, often leading, role in SKA science. All 13 science working groups and focus groups have Dutch members and several senior astronomers have previously led or are currently leading specific working groups. Astronomers at universities in the Netherlands (Amsterdam, Groningen, Leiden and Nijmegen) and at ASTRON carry out high-impact, world-class science with SKA precursors and pathfinders, such as LOFAR, WSRT-Apertif, ASKAP and MeerKAT and develop the detailed expertise that will be required to fully exploit the scientific capabilities of the SKA. The Dutch astronomy community also holds regular SKA-NL science meetings. The three universities of technology (Delft University of Technology, Eindhoven University of Technology and University of Twente) are involved in the engineering aspects of radio telescopes in areas such as antenna design and mitigation of radio frequency interference.
Contracts awarded
ASTRON and the academic partners work together with Dutch industry to build the following parts of the telescope:
- Imaging and calibration software for SKA
A Dutch team, consisting of software developers from industry and ASTRON, is making an important contribution to the software that converts the antenna signals into images of the (radio) sky. This is a complex process, called calibration, in which corrections are made to compensate for the effect of the ionosphere (a high layer in the earth's atmosphere) and the instrument itself. This builds on the valuable experience gained with LOFAR. The consortium building the software consists of TriOpSys, CGI, S[&]T and ASTRON.
- The correlator beamformer
The Low Central Signal Processor (CSP Low) processes the digital data coming from the SKA-Low antenna stations. CSP Low consists of four subsystems: CBF (correlator and beamformer), PSS (Pulsar search engine), PST (a machine that measures the arrival times of pulses) and LMC (the management and control system). A Dutch company is in charge of the production of these sub-systems, supplied by different countries, and is responsible for the integration, testing and final delivery of the CSP Low system. The Netherlands also supplies the hardware for the CBF, including servers with 420 Xilinx Alveo processing cards.
- The laser modules for the glass fibres
RFoF (Radio Frequency over Fibre) modules translate the radio waves captured by the antennas into light signals that can be transmitted over glass fibres for further processing. A Dutch company will produce and test 65,000 of these modules in the next few years.
Pathfinder telescopes
ASTRON operates two SKA pathfinders:
- LOFAR (above photo), the Low Frequency Array - part of the International LOFAR Telescope with its core in Exloo, the Netherlands. The technology used in LOFAR forms the basis for the design of the SKA’s low-frequency telescope.
- WSRT-Apertif (the Westerbork Synthesis Radio Telescope) (below photo) in Westerbork, the Netherlands.
Developing new technologies
Technological developments of LOFAR are highlighted in the special "10 years of LOFAR highlights", produced in 2020.
The technological development of the Apertif receiver for the WSRT is highlighted in this news article.
Case studies
In 2016, using LOFAR as a reference scenario, the Technopolis Group issued a report about the expected gains of the Netherlands joining the SKA project. The report (only available in Dutch) is entitled “Astronomische Welvaart?” (Astronomical Prosperity) and concluded the following:
“Dutch participation in the SKA will maintain or strengthen the Dutch top position in (radio) astronomy, depending on the size of the Dutch contribution. The SKA is considered a game-changing project in the field of Big Data, a technology field with great economic potential.”
In 2019, the Rathenau Institute, which researches the impact of science, innovation, and technology on society, conducted a review on the impact of large-scale research infrastructures, including LOFAR.
- Direct return on investment to the Netherlands on LOFAR during the construction phase of the telescope: 1.1 to 1
- Direct return on investment to the Netherlands on LOFAR during the operations phase of the telescope: 1.24 to 1
“The report [Tjong Tjin Tai et al., 2019] confirms with the Dutch example of LOFAR that returns in the country of establishment are relatively high when investing in a research infrastructure”, then Minister of Education, Culture, and Science Ingrid van Engelshoven said in 2019.
Return on investment for the Netherlands
The developments needed to build the SKA are relevant beyond science. Dutch participation in the SKA will be an important driver for innovation in ICT, e.g. knowledge developed to process large amounts of data can find application in retail analytics, industry 4.0 and energy-efficient computing. The progress in sensor technology in combination with real-time monitoring is relevant for traffic flows, security and healthy ageing.
Ingrid van Engelshoven, then Minister of Education, Culture and Science, said in 2019 about scientific projects like LOFAR and SKA: “Research infrastructures are a magnet for talent and knowledge-intensive companies. By collaborating with science on new technologies, industry can expand or improve its existing expertise to introduce new technologies to existing markets or enter new markets. Investing in research infrastructures therefore also means investing in new key enabling technologies for future solutions to societal challenges and new prosperity.”