Prototype dish for SKA-Mid telescope readies for ops

Staff Writer
By Staff Writer, ITWeb
Johannesburg, 29 Jan 2024
The SKA-MPIfR telescope in the Karoo semi-desert in South Africa. (Image credit: SARAO)
The SKA-MPIfR telescope in the Karoo semi-desert in South Africa. (Image credit: SARAO)

The Square Kilometre Array (SKA)-MPIfR Telescope in South Africa is ready for science operations.

So says the South African Radio Astronomy Organisation (SARAO). It notes the journey into the golden age of radio astronomy continues with the SKA telescopes, which will become the largest radio telescope arrays on Earth in the coming years.

The (SKA)-MPIfR Telescope prototype telescope is a facility of the Max-Planck Society and was established with the assistance of SARAO. It is jointly operated and maintained by the Max Planck Institute for Radio Astronomy (MPIfR) and SARAO.

According to the organisation, the MPIfR in Bonn played an active role in the prototype telescope’s development over the past decades. It says Germany will become a full member of the international SKA Observatory – the intergovernmental organisation currently building the telescopes in Australia and South Africa – in early 2024.

To develop key technologies with unique scientific benefits, the MPIfR, together with OHB Digital Connect GmbH and SARAO have built the SKA-MPIfR telescope, a prototype dish for the SKA-Mid telescope, for technical commissioning and scientific use.

The SKA-MPIfR telescope was fully assembled in mid-2018 at the South African SKA site in the Karoo semi-desert.

Initial test observations took place in December 2019 and technical commissioning − such as system evaluation, radio-frequency-interference testing and performance testing − took place until early 2022, leading to the SKA system design qualification documents published in 2022.

Since then, developments were pursued, setting up a framework to operate the SKA-MPIfR (SKAMPI) telescope remotely and as a robotic system, integrating telescope operations with frontend and backend control, and synchronising observations with data acquisition and automated calibration, says SARAO.

“With a fully-digital frontend, SKAMPI has two receiver units, for the S-band between 1.75GHz and 3.5GHz, and for the Ku-band between 12.0GHz and 18.0GHz,” says Gundolf Wieching, head of the electronics technical division at MPIfR.

“The receivers are based on the MPIfR S-band system designed for MeerKAT. The data acquisition and processing system or ‘backend’ is a high-performance computer system developed by the MPIfR, using predominantly graphic-processing-units as accelerator cards for computing in standard commercial servers.”

He explains that the backend system can be dynamically adapted to serve different science cases, like pulsars or spectropolarimetry observations.

Wieching adds that the size of SKAMPI with a projected aperture of 15m in combination with a site protected against radio frequency interference offers a rare combination of large field of view, and thus fast sky coverage, with excellent polarisation properties in order to investigate magnetic fields in the universe.

“We have performed first-light observations with SKAMPI in the S-band at frequencies between 1.75GHz and 3.5GHz, demonstrating the telescope’s spectral and pulsar capabilities with imaging of the radio emission of the Southern Sky and detection of the Vela pulsar,” says Hans-Rainer Klöckner from MPIfR, the SKAMPI project scientist.

“For SKAMPI, we have extended our software system so that computing resources not needed for the real-time signal processing of the current observation can be used by scientists for first automated analyses,” explains Tobias Winchen, also from MPIfR.

“The results are available shortly after the observations and so provide fast feedback of the observations and system performance. Soon we will start testing a fully automated system that includes the output of the automated analyses to manage the entire observations of a scientific programme.”

Although much of the observing time on SKAMPI will be dedicated to science programmes, SARAO notes that requests for observations will be open to the South African and German communities. There will also be an opportunity to set up an educational programme for schools and universities.