The discovery of terrestrial, swept-frequency emission that mimics an interstellar dispersive delay

We will detail the discovery of an anomalous terrestrial source of pulsed emission which exhibits a frequency-swept signal that closely mimics the frequency-dependent delay induced by dispersion in interstellar plasma. The signals were detected through the far sidelobes of Parkes Radio Telescope, appearing in all of the 13 independently-positioned receivers installed at the dish focus. The frequency-dependent delay and the sweep rates for most of the bursts are similar to those of a burst previously purported to be extragalactic. These bursts both call into question the extragalactic nature of that burst, and highlight the limitations of performing searches for one-off impulses with single dishes, in that they experience ambiguity in the positional localization of burst origins.