Polarisation performance and calibration of the digital beamforming system for 2-PAD

In this paper, we report on calibration and polarisation performance of the 2PAD digital beamforming system, a pathfinder instrument for large-N, high-frequency phased-array radio instruments, in particular the Square Kilometre Array (SKA) radio telescope. We review the design of the digital system, and report on instrumental calibration approaches.