Approaching a technological challenge on the scale of the SKA Telescope is formidable.
The Square Kilometre Array once complete will provide a million square metres of collecting area, with millions of radio telescopes, comprising dishes, dipole antenna and apertyire array instruments connected using the highest speed communications network ever envisaged in the field of astronomy, feeding data at rates which will dwarf modern data transmission scales over the Internet.
This huge increase in scale demands a revolutionary break from traditional radio telescope design and radical developments in processing, computer speeds and the supporting technological infrastructure.
Three types of radio telescopes, being dishes, mid frequency aperture arrays and low frequency aperture arrays, will be used by the SKA to provide continuous frequency coverage from 50 MHz (6 m wavelength) to 20 GHz (1.5 cm wavelength).
Combining the signals from the antennas over this wide a frequency range will generate so much data, that local stations will be required just to combine and reduce it to more manageable packages for distribution to supercomputers and then on to scientists all over the world.
Built over two sites in Australia and Africa, the SKA will achieve both high sensitivity and high resolution images by having antennas densely distributed in the central region of the arrays and then positioned in clusters along five spiral arms – the clusters will become more widely spaced further away from the centre.
A phased approach: The construction of the SKA will be phased. Phase one (SKA1) will constitute about 10% of the array and will include dishes and low frequency aperture arrays.
Phase two (SKA2) will extend the array with mid frequency aperture arrays and dishes. The phased construction of the telescope will mean that the SKA can start operating and producing valuable science before overall construction is completed.
Phase 1: Will take place between 2018 and 2023.whilst Phase 2 work will commence in parallel to be completed soon after phase 1
The SKA will drive technology development particularly in information and communication technology.
Spin off innovations in this area will benefit other systems that process large volumes of data from geographically dispersed sources. The computing requirements of the SKA will exceed those of the fastest supercomputers available in 2013, whilst the data processing and amounts of data will compete with that generated by the entire Internet, facilitating the need for a new kind of high speed network.
The energy requirements of the SKA, with its remote locations isolated from major power grids also presents an opportunity to accelerate technological development in scalable renewable energy generation, distribution, storage and demand reduction.
Pivotal SKA technology is being demonstrated with a suite of precursor and pathfinder telescopes and with design studies by SKA groups around the world. Key SKA technologies will be derived from these and many solutions will be selected and integrated into the final instrument.
The following table gives an indication of the technical specifications for the SKA radio telescopes. You may wish to consult our detailed glossary of terms relating to radio and general astronomy
|Frequency range||50 MHz (6 m wavelength) to 20 GHz (1.5 cm wavelength)|
|Sensitivity area / system temperature||5 000 m²/K (400 μJy in 1 minute) between 70 and 300 MHz|
|Survey figure-of-merit||4×107 – 2×1010 m4K-2 deg2 depending on sensor technology and frequency|
|Field-of-view||200 square degrees between 70 and 300 MHz1-200 square degrees between 0.3 and 1 GHz1 square degree maximum between 1 and 10 GHz|
|Instantaneous bandwidth||Band centre ± 50%|
|Spectral (frequency) channels||16 384 per band per baseline|
|Calibarated polarisation purity||10 000:1|
|Synthesised image dynamic range||>1 000 000|
|Imaging processor computation||1018 operations/second|
|Final processed data output||10 GB/second|