This work package (WP2) was the over-arching international activity for the engineering design of the SKA and addressed both short and long-term challenges. It was expected that the costed system design would be completed by 2012, to be followed by detailed design, production engineering and tooling in 2013 and 2014, and construction start (Phase 1) in 2015. (Construction start is now expected in 2018.) WP2 was led by Professor Richard Schilizzi, Director of the SKA Program Development Office (SPDO), located at the University of Manchester.
The costed system design was achieved by a process which continued definition and design of the SKA concept within the astronomy and engineering communities, set and reviewed the specifications for the SKA, undertook cost and performance analysis studies, examined trade-offs, and formulated conceptual SKA and detailed Phase 1 system designs. The adopted designs reflect inputs from manufacturing, operations, instrument support (including maintenance) and life cycle studies performed as part of the project, as well as from regional Precursors, Pathfinders and Design Studies.
The SKA project has been pursuing technologies for realizing low-cost receptors with the sensitivity required and performance to meet ambitious single-field and survey sensitivity goals. There are different optimum receptor technologies for different frequency bands, with frequencies < 0.3 GHz being the domain of sparse aperture arrays (e.g. LOFAR, MWA and LWA). From 1 to 10 GHz, parabolic dishes with wideband, single-pixel feeds are a feasible technology. Very wideband single-pixel feeds covering the full range are under development and need to show that their sensitivity and performance makes a cost effective solution. The fall-back is to use narrow band feeds with an indexing arrangement. Over the range 0.3 – 1 GHz the single-pixel solution is again likely to be viable but the Aperture Array (AA) and Phased Array Feed (PAF) Wide Field of View (WFoV) technologies promise very significant additional scientific benefits through their enhanced survey speed capability, and could replace single pixel feeds in this range if they can achieve the necessary cost, sensitivity and imaging performance. It should be noted that the pursuit of multiple options increases the likelihood that at least one WFoV feed technology will prove viable on SKA development timescales.
Two major verification programs were carried out during the course of PrepSKA: the Dish Verification Program (DVP) and the Aperture Array Verification program (AAVP). These were 4 year programs and were completed at the end of 2012, in time to fit in with the PrepSKA no-cost extension to Dec 2012.
Many documents were provided for each sub-workpackege, and links to these are given in the CoDR sub-page tab.
The deliverables for this workpackage can be found at the links below.
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