Using Multiple Beams to Distinguish RFI From ETI Signals
Gerry Harp (SETI Inst.) gharp@seti.org

The Allen Telescope Array is a multi-user instrument and will perform simultaneous radio astronomy and SETI observations. It is a multi-beam instrument, with 16 independently steerable dual-pol beams at 4 different tunings. Given 4 beams at one tuning, it is possible to discriminate RFI from true ETI Signals by pointing the beams in different directions. Any signal that appears in more than one beam can be identified as RFI and ignored during SETI. We discuss the effectiveness of this approach for RFI discrimination using realistic simulations of the ATA-350. We find, for example, that there is only 1% probability that RFI present in one beam will appear at 10x smaller levels in the other 3 beams.