the instruments are functioning correctly. The dishes are equipped with a number of high performance single pixel feeds to cover frequencies from 580 MHz up to 14 GHz. Murchison Widefield Array (MWA) The Murchison Widefield Array is a low-frequency radio array operating in the frequency range 80–300 MHz that began upgraded operation in 2018 at the Murchison Radio-astronomy Observatory site in Western Australia. Hydrogen Epoch of Reionization Array (HERA) The HERA array is located in the South African Karoo Radio Astronomy Reserve. It is designed to study highly redshifted atomic hydrogen emission emitted prior to, and during the epoch of reionization. Pathfinders APERture Tile in Focus (Apertif) Very Long Baseline Interferometry Electronic MultiBeam Radio Astronomy ConcEpt e-MERLIN Expanded Very Large Array Long Wavelength Array SKA Molonglo Prototype (SKAMP) NenuFAR Giant Metrewave Radio Telescope Allen Telescope Array The Allen Telescope Array in California uses innovative 6.1m offset Gregorian dishes equipped with wide band single feeds covering frequencies from 500 MHz to 11 GHz. The 42-element array in operation by 2017 is to be extended to 350 elements. The dish design has explored methods of low-cost manufacture. LOFAR LOFAR —a €150 million Dutch-led project— a novel low-frequency phased aperture array spread over northern Europe. An all-electronic telescope covering low frequencies from 10 to 240 MHz, it came online from 2009 to 2011. LOFAR was in 2017 developing crucial processing techniques for the SKA. Design studies Aperture Array Verification Programme Canadian SKA Program Preparatory Study for the SKA Square Kilometre Array Design Studies (SKADS) Electronic MultiBeam Radio Astronomy ConcEpt (EMBRACE) BEST Data challenges The amount of sensory data collected poses a huge storage problem, and will require real-time signal processing to reduce the raw data to relevant derived information. In mid 2011 it was estimated the array could generate an exabyte a day of raw data, which could be compressed to around 10 petabytes. China, a founding member of the project, has designed and constructed the first prototype of the regional data processing centre. An Tao, head of the SKA group of the Shanghai Astronomical Observatory, stated, "It will generate data streams far beyond the total Internet traffic worldwide." The Tianhe-2 supercomputer was used in 2016 to train the software. The processing of the project will be performed on Chinese designed and manufactured Virtex-7 processors by Xilinx, integrated into platforms by the CSIRO. China has pushed for a unified beam forming design that