Strategies for spectrum coexistence between radio telescopes and satellite networks

Abstract Passive services (e.g. radio astronomy, Earth observing) are slowly responding to new radio frequency interference (RFI) challenges to their science missions, particularly those arising from constellations of communication satellites. We will report on efforts at the National Radio Astronomy Observatory and Green Bank Observatory to detect, characterize and mitigate RFI impacts at our sites, including (a) preliminary results from a prototype spectrum monitor located at Green Bank; (b) results from a 1.5-year study of the impacts of Starlink transmissions (satellites and user terminals) on the Very Large Array, indicating minimal interference; (c) our plans for real-time status coordination of telescope control systems with satellite operators to avoid RFI conflicts with observing programs. Future scientific endeavors such as the next-generation Very Large Array will operate in a more complex spectral environment than the current generation of radio telescopes, and the ability to accurately detect, characterize and effectively mitigate RFI is critical.