Spatial filtering of RF interference in radio astronomy using a reference antenna

Radio astronomical observations are increasingly contaminated by RF interference. Assuming an array of telescopes, we have previously considered spatial filtering techniques based on projecting out the interferer array signature vector. In this paper, we consider extending the astronomical array with a reference antenna (or array), and develop spatial filtering algorithms for this situation. The information from the reference antenna improves the quality of the interferer signature vector estimation, hence more of the interference can be projected out. The conditioning of the problem improves as well. The algorithms are tested both on simulated and experimental data.