This work package (WP2) is the over-arching international activity for the engineering design of the SKA and addresses both short and long-term challenges. It is expected that the costed system design will 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. WP2 is led by Professor Richard Schilizzi, Director of the SKA Program Development Office (SPDO), located at the University of Manchester.
The costed system design will be achieved by a process which continues definition and design of the SKA concept within the astronomy and engineering communities, sets and reviews the specifications for the SKA, undertakes cost and performance analysis studies, examines trade-offs, and formulates conceptual SKA and detailed Phase 1 system designs. The adopted designs will 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 will be carried out during the course of PrepSKA: the Dish Verification Program (DVP) and the Aperture Array Verification program (AAVP). These are 4 year programs and will be completed at the end of 2012 with post-PrepSKA funding now under consideration.
WP2 will end on 31 March 2012.