The site is about 700km north of Perth, and 350km east of Geraldton, in Western Australia. Formerly a pastoral station with sheep and cattle, the site is in the Murchison Shire which covers a land area of 49,500 square kilometres. The Shire is the size of a small European country but has a population of only about 100 people!
Low population density, coupled with a legislated radio-quiet zone, and cutting-edge infrastructure has facilitated major new discoveries by the current telescopes and established the site as one of the world’s premiere radio astronomy facilities.
Launched in 2012, the observatory currently hosts two SKA precursor telescopes, our ASKAP radio telescope and the Curtin University-led Murchison Widefield Array (MWA). These instruments are enabling new discoveries and paving the way for the SKA telescopes.
The observatory is located in the heart of Wajarri Yamaji country. Aboriginal people have lived in Australia for tens of thousands of years (up to 70,000 years) and the Wajarri Yamaji have lived in the Mid West region of Western Australia for much of this time.
Stories about the stars form a crucial part of Wajarri lore and the Wajarri Yamaji have many stories about the stars, galaxies and shapes that they have observed in the night sky.
In 2017, the Wajarri Yamaji received legal recognition of their land and culture from the Federal Court of Australia. The Court’s Determination recognises the long-standing Wajarri Yamaji connection to Country.
Before its establishment, the Australian Government, CSIRO and the Wajarri community negotiated an Indigenous Land Use Agreement (ILUA) for the observatory. This agreement allows the current telescopes to operate. In exchange the Wajarri Yamaji receive long term benefits to the community. A new ILUA has been signed, which covers current observatory operations with the addition of the SKA-Low telescope, for 50 years.
For the new ILUA, a heritage survey was conducted, whereby Wajarri people walk over the proposed telescope site, surveying the area for any culturally significant artefacts or sites. We are working with the Wajarri Yamaji heritage service provider and other experts to thoroughly survey the land. We are grateful to the Wajarri community for working with us to enable the development of this unique scientific facility.
Radio telescopes are designed to detect faint natural radio signals from space, but this also makes them very sensitive to the interference caused by man-made radio transmissions. This radio frequency interference can be caused by radio transmitters such as mobile phones, two-way radios and broadcasting towers, or by electrical equipment such as vehicles, appliances or electrical machinery.
The main reason to build an observatory in such a remote location is to avoid interference from Earth-based radio transmissions that interfere with sensitive radio astronomy receivers. In the same way that it is necessary for us to avoid city street lights when trying to observe the night sky with our eyes, radio astronomers must distance themselves from radio communications networks that allow mobile phones and other services to operate.
The Australian Radio Quiet Zone WA (ARQZWA) was established by the Australian and Western Australian Governments to protect radio astronomy receivers from harmful radio interference, while allowing for opportunities for coexistence with other activities.
The ARQZWA is centred on the observatory and covers an area 520km in diameter. Within the radio quiet zone, licensed communications and electronic devices such as television transmitters, mobile telephones base stations and CB radios are controlled to limit electromagnetic interference to the radio telescopes on the site.
Due to these radio-quiet requirements, it’s not possible to visit the site in person, except during our open day events. If you’d like to join the list to be notified of our next open day, please contact us.
The observatory’s control building houses the ASKAP and MWA correlators, sophisticated computing systems that process the massive pipeline of data that streams from the telescopes.
ASKAP’s 36 antennas send analog radio signals via optical fibers to the building where they are digitised, processed to form 36 beams from each antenna, and combined to turn all the 36 antennas into one giant telescope. The MWA correlator uses off-the-shelf fast computing hardware to combine signals from 512 tiles of antennas.
Massive steel doors at the entrance to the control building form an airlock to ensure that the radio frequency emissions from the computers inside can’t escape outside to pollute the pristine radio-quiet environment of the observatory. The building also houses chillers that extract waste heat from the correlators and transfer it to a large bore-field, making use of the cooler temperatures underground.
CSIRO is designing a new control building to house the SKA-Low correlator which will process the telescope data and send it to the Pawsey Supercomputing Research Centre, in Perth for imaging.
Powering the observatory
CSIRO has built a dedicated off-grid solar-hybrid power station consisting of a 1.85 MW solar array, a lithium-ion battery that can store 2.5 MWh of electrical energy, and four diesel generators. It is the world’s first hybrid-renewable facility to power a large remote astronomical observatory. It was built by Horizon Power and Energy Made Clean (EMC) in partnership with CSIRO.
CSIRO modelling indicates the photovoltaic system and storage battery saves up to 800,000 litres of diesel a year and cuts carbon dioxide emissions by about 2,000 tonnes a year. What makes this power station unique is the RFI shielding, designed by CSIRO. The shielding keeps electromagnetic interference to levels that don’t harm the radio astronomy observations.
Preparing for SKA-Low
We led a team working in collaboration with industry partners to design the infrastructure for the SKA-Low telescope, including roads, control buildings, a power station, and water and sanitation facilities. The designs were completed in 2018 and include 210km of power supply and fibre-optic trenching for the telescope’s array of antennas and 200km of access tracks.
The staggering amounts of data collected each second by the SKA-Low antennas will be transmitted via 65,000 fibre optic cables to the telescope’s site-based supercomputing facility. That facility has required innovative thinking to help solve the problem of how to contain the radio frequency interference generated by the computers. The building has been designed as a fully welded box within a box, very similarly to the current control building for the precursor telescopes. The inner box will house computing equipment within an inner shield, and support plant equipment will be within an outer shield.
With construction due to start in 2022, we are also involved in managing SKA-Low construction. Along with industry partners, we will be overseeing the infrastructure construction and antenna installation contracts.
There is much to be done to provision for new facilities, from planning for new expanded permanent accommodation at the observatory and in Geraldton and Perth, through to working on the management of construction contracts.
Being site-ready will also mean dealing with various road and land use permits and provision of electricity requiring a small on-site power station with a very high level of renewable energy.
Throughout this process, it’s also critical to ensure that the project design, construction planning and operations pay acute attention to the radio quiet zone restrictions, to ensure they don’t impact the currently operating telescopes.