UV-plane coverage analysis for the BEST project (SKA-DS)

The Northern Cross radiotelescope in Medicina is being used by the Basic Element for SKA Training project (BEST, Montebugnoli et al. 2006) as test bed for technological developments aimed at the Square Kilometer Array (SKA),within the SKA-Design Studies (SKA-DS) programme. In the framework of these activities, 6 of the 24 East-West arm sections of the original telescope will be refurbished, along with 14 of the 64 North-South cylinders. The upgraded sections will be operated as an interferometer and used to test real-time beam forming procedures and software as well as interference mitigation. Since only part of the original telescope can be upgraded, it is mandatory to find out the best set of EW sections and NS cylinders which optimize the interferometer beam response. Some limitations arising from the previous stages of the project (BEST-1 and BEST-2) substantially constrain the choice of the position of the elements to be upgraded (see Sect. 2). The selection has been carried out first by a 1-D analysis for each arm (Sect. 3). Subsequently, the 2-D response of the full interferometer is computed and analyzed (Sect. 4). We present conclusions and recommendations for sections and cylinders to be refurbished in Sect. 5.