Status update on the system verification of APERTIF, the Phased Array Feed system for the Westerbork Synthesis Radio Telescope

The APERTIF (APERture Tile In Focus) project aims to install Phased Array Feeds (PAFs) in the 25m diameter reflector antennas of the Westerbork Synthesis Radio Telescope (WSRT). These PAF systems can simultaneously form 37 compound beams on the sky and will replace the current single beam horn feeds. The survey speed of the WSRT will be improved significantly, bringing down the time to execute a deep wide-field astronomical survey by a few orders of magnitude. The detailed design phase is completed and samples of final hardware have been tested (W.A. van Cappellen and J.G. Bij de Vaate, XXXIth URSI GASS, 2014, pp. 1–4). Three WSRT dishes are equipped with this hardware, with the aim to reconfirm system performance, before starting full production.