Exploring RFI Reduction Techniques on CH 3.3 GHz Observations using the Arecibo Observatory 12-Meter Telescope

As the effects of Radio Frequency Interference (RFI) on astronomical data increases with our use of technology, so too does the necessity of novel approaches to mitigate its effects. We discuss the application of the Generalized Spectral Kurtosis estimator as a tool for identifying and excising RFI in radio astronomy data. In particular, we demonstrate the usefulness of this technique using S-band (3.3 GHz) observations from the recently upgraded 12-meter telescope at the Arecibo Observatory. This frequency band is particularly fraught with RFI given the juxtaposition of both wifi routers and mobile phone transmissions, yet it encompasses important spectral line transitions for astronomical observations, including the CH hyperfile transitions near 3.3 GHz. We use data from a pilot survey of the Galactic Center at this frequency to test the efficacy of the generalized spectral kurtosis estimator. This dataset contains RFI with varying characteristics including both narrow and wideband features as well as signals that are both stable and drifting in frequency, serving as an excellent testbed. We show that this method is effective at identifying all types of RFI present in the dataset. We discuss the successful implementation of this method as well as our plans to implement it in a large scale galactic plane survey.