SKA Hybrids Involving the US LNSD COncept

摘要

The likely Key Projects for the SKA demand both a large frequency range (potentially 0.06-24 GHz) and a large range of fields of view (potentially less than 1 deg(2) at higher frequencies to as much as 200 deg(2) below 1 GHz). The US SKA Consortium has proposed the Large Number/Small-Diameter (LNSD) concept, which generally covers the frequency ranges and fields of view required by the Key Projects. Opportunities do exist, however, to enhance the design of this concept and provide access to larger ranges of frequency and field of view. We describe a number of 'hybrid' arrays, involving the LNSD concept, that are designed to increase the probability that most of the SKA Key Projects can be conducted. There are two broad classes of hybrids, those that combine concepts and those that combine technological aspects from the different international groups. We consider how the US LNSD concept could form the basis of both kinds of hydrids. We focus on two 'strawman hybrids.' The first is an SKA composed of high- and low-frequency sub-arrays, with the LNSD concept forming the high- frequency sub-array.