Characterizing the Increasing Prevalence of Radio Frequency Interference at the South Pole's Dark Sector

Radio Frequency Interference (RFI) can impact astronomical measurements when radio signals produced by artificial devices, such as cell phones and satellites, interfere with sensitive instrumentation. Instruments that are especially vulnerable to RFI can be placed in radio quiet or “dark” sites, typically remote areas where transmissions are restricted to protect instrumentation from interference. RFI can be a problem for Cosmic Microwave Background (CMB) experiments, as their technology makes them sensitive to a broad range of frequencies. As more commercial satellites are launched and as portable consumer electronic devices utilize an increasingly broad range of the electromagnetic spectrum, the prevalence of RFI is increasing, even at remote radio-quiet sites. We analyzed publicly available data collected by a dedicated RFI monitor operated by the BICEP/Keck team alongside their CMB survey instruments. This RFI monitor has run almost continuously in the South Pole’s Dark Sector since 2014, which provides a long and comprehensive record of RFI to study its prevalence by season and over time. Understanding long term trends in the prevalence of RFI can help in understanding its impact on survey sensitivity and inform future mitigation efforts.