As the largest and most sensitive telescope ever envisioned, the Square Kilometre Array (SKA), a radio telescope under development by a consortium of 20 countries, will revolutionize our knowledge of the universe through large-area imaging from 70 MHz to a 10 GHz when it is deployed in the middle of the next decade. On the path to the development of the SKA, the Australian SKA Pathfinder (ASKAP) is at a key SKA science frequency band of 700 MHz to 1.8 GHz. ASKAP seeks to achieve instantaneous wide-area imaging through the development and deployment of phased-array feed systems on parabolic reflectors. This large field of view makes ASKAP an unprecedented survey telescope poised to achieve substantial advances in SKA key science.
The Commonwealth Scientific and Industrial Research Organisation, or CSIRO, is an Australian government-funded research agency. A division called CSIRO Astronomy and Space Science (CASS) is undertaking construction of the ASKAP (see www.csiro.au/org/CASS.html). The combination of location, technological innovation and scientific program will ensure that ASKAP is a world-leading radio astronomy facility, closely aligned with the scientific and technical direction of the SKA. CSIRO is also involved in the development of the SKA, which is anticipated to be operational in 2024.
Currently under construction in outback Western Australia at the Murchison Radio Astronomy Observatory (MRO), ASKAP will consist of an array of thirty-six 12-meter dishes (Figure 1
), each employing advanced phased-array feeds (PAFs) to provide a wide field of view: 30 square degrees. As opposed to conventional antenna optics, PAFs allow for multiple configurable beam patterns using digital electronics to implement beamformers. ASKAPís location in the Southern Hemisphere is advantageous for astronomy. Combined with a very large radio quiet zone (an area where radio frequency emissions are managed), the result will be a radio telescope with unprecedented performance.
Figure 1 Ė The first ASKAP reflector surface is being installed in Western Australia; researchers will later add a phased-array feed at the focus of the antenna.
ASKAPís wide field of view and broad bandwidth will enable astronomers to survey the sky very quickly, but present a signal-processing challenge two orders of magnitude greater than that facing existing telescopes. To satisfy performance demands of approximately 2 peta operations/second with 100-Tbit/s communications, Xilinxģ FPGAs deliver a well-balanced mix of these features. FPGAs provide an economical solution for both power consumption and capital cost compared with other alternative solutions, such as high-performance computing (HPC).