A study was conducted to determine if using the non-zero spacing channels (visibilities) in synthetic aperture radiometers could help with the detection of radio frequency interference (RFI) at L-band. The study was conducted using RFI filters developed for the airborne synthetic aperture radiometers ESTAR and 2D-STAR and data collected with 2D-STAR. The ESTAR filter employed a combined threshold/change detector on the total power (zero spacing in the synthetic aperture radiometers). The new approach taken for the 2D-STAR filter employs a threshold on the maximum of all non-zero spacing visibilities in a sample. The filter using all visibilities demonstrated a significant performance advantage, with lower incidence of both missed detections and false detections than the filter using total power.