The existing FM radio transmissions will not be restricted and reception will remain as it is. Existing television reception will change across the whole of South Africa as a result of the national project led by the Department of Communications to migrate from terrestrial analogue to terrestrial digital television transmissions. This change will also lead to a greater use of satellite reception in remote communities. The establishment of terrestrial digital television transmissions will need to comply with the protection requirements for the SKA. However, all television and radio services in South Africa are broadcasted via satellite covering the whole country, which will not be affected. Government has a policy in place to subsidise the poorest households for the migration cost to the new digital television transmissions, including satellite reception in the Northern Cape in areas affected by the SKA.
The availability of existing cell phone coverage around the SKA central infrastructure is sparse. Due to the high sensitivity of radio astronomy receivers within the SKA area, existing cell phone coverage still causes unacceptable interference to certain parts of the SKA central infrastructure and will need to be restricted. The circular area within a radius of about 80 km from the SKA Virtual Centre is the area where existing usable cell phone signals may be affected. However, cell phone coverage in the towns such as Carnarvon, Van Wyksvlei and Williston will not be affected. To compensate for the loss of communication within the affected area, and also to support SKA operations, an alternative radio communication system that will not interfere with the SKA is being planned for future deployment. It will be an advanced multi-channel duplex radio communication system that will operate with mobile, handheld and fixed radios. The network will use similar frequencies to the existing low frequency mobile communication network (‘Marnet’), which will not be affected by the protection requirements. Additionally, a scheme for low cost satellite VSAT communications is being set up to provide for telephony and internet access.
The only possibility of an effect on electrical machinery or activities may be those located close to the Central SKA Infrastructure (up to 36 km from centre) or close to a remote SKA station (up to 16 km), depending on topography. Very few interference situations are expected, which can be attended to individually when they are identified, and would not involve any of the towns in the area.
The study to locate the SKA in South Africa started in 2003 when a thorough study on the suitability of existing and expected conditions in South Africa was carried out to consider hosting the SKA. In South Africa, the Northern Cape Province is by far the most suitable area with the lowest population and industrial density together with the lowest volume of radio communication and electrical activities. Three areas were considered in the Province, i.e. Kalahari, Karoo and Namaqualand. Karoo turned out to be the better option. Notwithstanding the low economic activity density, the Karoo does offer the basic infrastructure required to support the SKA alongside good atmospheric conditions, radio quietness, geotechnical stability and good security conditions. On a global basis, six countries thought that they may offer acceptable conditions but only Western Australia and the Northern Cape Province met the requirements but with the latter being the better option.