Memo 57 SKA system definition and costing : a first approach

Despite the existence of several antenna concepts for the SKA much of the instrument’s top-level design can be described in terms that are common to all concepts. This is not surprising of course since a great deal of the design process centres on transporting and processing common information volumes and rates derived from prescribed fields-of-view, observing bandwidths etc. In this short paper we outline a first attempt at a top-level description, and at estimating the basic performance and cost of putative arrays. The first version of the estimation tool is directed mainly at engineers but as the package is refined the tools should prove useful to a wider group. Most importantly, the system definition process has already provided a framework for continuing system design and development, principally via task forces within the SKA International Engineering Working Group.