Element rotation tolerance in a low-frequency aperture array polarimeter

Abstract

We present a rotation error tolerance analysis for dual-polarized dipole-like antennas commonly found in low-frequency radio astronomy. A concise Jones matrix expression for the phased array is derived which facilitates calculations of rotation error effects in polarimetry. As expected, for random rotation error and number of elements approaching infinity, the estimation error converges to that of the error-free case. However, as in practice large but finite number of antennas are involved, we present a simple analysis to estimate rotation error effects. An example calculation based on a “baseline” design for a low-frequency Square Kilometre Array (SKA) “station” is discussed.