The telescope sites
Radio astronomy requires radio quietness - the absence of all the electronic noise that human beings create with their technology. This noise, known as radio frequency interference (RFI), is to radio astronomy what light pollution is to optical astronomy.
The two SKA telescope sites have been chosen due to their radio quietness. In South Africa, the SKA-Mid site is within the Karoo Central Astronomy Advantage Area, while in Western Australia, the SKA-Low site is within CSIRO's Murchison Radio-astronomy Observatory, on the traditional lands of the Wajarri Yamaji.
These sites enjoy the national regulatory status of radio quiet zones that protect them from ground-based interference, making them ideal for radio astronomy observations, as the SKA precursor telescopes MeerKAT and HERA in South Africa, and ASKAP and MWA in Australia, have already demonstrated.
The SKA telescopes are designed to ensure that very little RFI is self-generated, and that it is controlled by the infrastructure as much as possible. This also means all the buildings which will house computing equipment on site will be thoroughly shielded, to ensure there is no interference with observations.
The recent boom in satellite mega-constellations poses additional challenges for professional astronomy because of their impact on observations at radio (as sources of RFI), optical (due to reflecting sunlight) and infrared (due to trapping heat) wavelengths. Mitigations are possible and thanks to constructive engagement with satellite operators so far, the SKAO has identified a path that limits the impact on the SKA telescopes while imposing limited constraints on satellite operators.
Beyond the sites
Australia and South Africa will also host facilities beyond the telescope sites themselves where critical scientific and technical support for SKAO operations will take place. Science Operation Centres and Science Processing Centres will be located in Perth and Cape Town, Engineering Operations Centres in Geraldton and Klerefontein, and during construction Integration Test Facilities in Geraldton and Cape Town will test as much of the telescope system as possible in a controlled laboratory environment before deployment on site