S. Ellingson, R.M. Buehrer, J. Budhu, S.V. Hum, W. Howard, A. Yip


Traditional methods for mitigation of interference in radio astronomy rely on avoiding interference where possible, and cutting out afflicted data when not possible. We have been working on the alternative of spatial nulling of interference facilitated by electronically-reconfigurable surfaces (e.g., reflectarrays) integrated into the design of the main and/or secondary reflectors of radio telescopes. Using full-wave electromagnetic simulations, we have demonstrated that spatial nulling of LEO satellites in this way is indeed plausible, and furthermore can be done with negligible effect on either main lobe characteristics or effective aperture. In particular, we have developed suitable surface designs as well as control algorithms that can track LEO satellites and succeed even when the quiescent pattern of the radio telescope is imperfectly known.