Hazards and future improvements to HI surveys

Abstract

Most radio astronomical observations are affected to some degree by man-made and natural interference. There are a few avoidance techniques that can reduce the impact of interference to the survey, but we must make quite significant advances in the understanding of our antennas and receivers and the interference itself before a substantial improvement can be expected. A major increase in the efficiency of future surveys will likely come from phased-array feeds, which have the potential for much closer beam spacing, greater antenna efficiency, and wider fields of view than current independent-feed arrays.