The Australian SKA Pathfinder

摘要

The Australian Square Kilometre Array Pathfinder (ASKAP) will be the fastest cm-wave survey radio-telescope and isunder construction on the new Murchison Radio-astronomy Observatory (MRO) in Western Australia. ASKAP consistsof 36 12-meter 3-axis antennas, each with a large chequerboard phased array feed (PAF) operating from 0.7 to 1.8 GHz,and digital beamformer preceding the correlator. The PAF has 94 dual-polarization elements (188 receivers) and thebeamformer will provide about 36 beams (at 1.4 GHz) to produce a 30 square degree field of view, allowing rapid, deepsurveys of the entire visible sky. As well as a large field of view ASKAP has high spectral resolution across the 304MHz of bandwidth processed at any one time generating a large data-rate (30Gb/sec in to the imaging system) thatrequires real-time processing of the data. To minimise this processing and maximise the field of view for longobservations the antenna incorporates a third axis, which keeps the PAF field of view and sidelobes fixed relative to thesky. This largely eliminates time varying artefact in the data that is processed.The MRO is 315 kilometres north-east of Geraldton, in Western Australia’s Mid West region. The primaryinfrastructure construction for ASKAP and other telescopes hosted at the Murchison Radio-astronomy Observatory hasnow been completed by CSIRO, the MRO manager, including installation of the fibre connection from the MRO site toPerth via Geraldton. The radio-quietness of the region is protected by the Mid West Radio Quiet Zone, implemented bythe Australian Federal Government, out to a radius of 260km surrounding the MRO.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.