Coherent Time-Domain Canceling of Interference for Radio Astronomy

TL;DR

This paper reviews coherent time-domain canceling (CTC) for radio astronomy interference mitigation, analyzing its capabilities and limitations with new metrics, motivated by emerging communication threats.

Contribution

It provides a comprehensive study of CTC's effectiveness and limitations using relevant metrics, addressing a gap in understanding and implementation.

Findings

CTC can significantly reduce interference power.

Noise increase due to CTC is quantifiable.

Limitations of CTC are identified under various conditions.

Abstract

Radio astronomy is vulnerable to interference from a variety of anthropogenic sources. Among the many strategies for mitigation of this interference is coherent time-domain canceling (CTC), which ideally allows one to "look through" interference, as opposed to avoiding the interference or deleting the afflicted data. However, CTC is difficult to implement, not well understood, and at present this strategy is not in regular use at any major radio telescope. This paper presents a review of CTC including a new comprehensive study of the capabilities and limitations of CTC using metrics relevant to radio astronomy, including fraction of interference power removed and increase in noise. This work is motivated by the emergence of a new generation of communications systems which pose a significantly increased threat to radio astronomy and which may overwhelm mitigation methods now in place.