Calibration of Mid-Frequency aperture array stations using self-holography

The stations (subarrays) of the Mid-Frequency Aperture Array (MFAA) system for the Square Kilometre Array (SKA) operating in the 450-1450 MHz range are envisaged to have ~ 10³ to ~ 10⁴ receive paths. This will make standard calibration procedures based on the array covariance matrix computationally expensive. In this paper, I therefore propose a method to calibrate the receive path gains during regular observations by correlating the signals from individual receive paths with the signal from a reference beam formed by the same station, i.e., “self-holography”. I discuss the performance of this approach using simulations for a realistic MFAA scenario.