Real-time RFI Mitigation Techniques in Radio Astronomy and Their Practical Limitations

TL;DR

This paper reviews current real-time RFI mitigation techniques in radio astronomy, discussing their effectiveness, limitations, and the need for combined technical and policy solutions to protect astronomical observations.

Contribution

It provides a comprehensive overview of state-of-the-art RFI mitigation methods and introduces new ideas like satellite avoidance and intelligent surfaces for interference reduction.

Findings

Filtering and digital processing are effective but have limitations.

Scheduling and intelligent surfaces can help mitigate interference.

Strong cooperation with spectrum regulators is essential for future radio astronomy.

Abstract

Radio astronomy is facing critical challenges due to an ever-increasing human-made signal density filling up the radio spectrum. With the rise of satellites, mobile networks, and other wireless technologies, radio telescopes are struggling with radio frequency interference (RFI), which can masquerade, block or distort astronomical signals. In this chapter, we explain where RFI comes from, how it affects observations, and discuss different ways to reduce or remove interference. The techniques presented here reflect the state of the art in real-time RFI mitigation at the time of publication and include methods such as filtering, digital processing, and optimal scheduling. The proposed catalogue also explores new ideas like satellite avoidance through scheduling, the use of intelligent surfaces to block interference, and advanced computer algorithms to clean up data. The chapter also highlights the need for strong cooperation between astronomers and spectrum regulators to protect radio frequencies for future discoveries. By combining technical solutions and better policies, we can help ensure that radio astronomy continues to provide important insights into the universe.