Improving the Murchison Widefield Array tile model for polarimetry

Abstract

This paper summarizes the progress to date in improving the Murchison Widefield Array's (MWA) “tile” model for polarimetry. A simple model that accounts for inter-element mutual coupling is presented which explains the false polarization leakage in Stokes Q (“false Q”) seen when the array is scanned away from zenith in the principal planes. On these planes the model predicts current imbalance in the X (E-W) and Y (N-S) dipoles and hence the false Q. More sophisticated models intended to calibrate actual observation data will be briefly discussed.