Speaker
Description
Systematic effects are a major obstacle in 21 cm radio interferometry,
where faint cosmological signals are obscured by instrumental and
observational contamination. This work presents a set of diagnostic
methods designed to detect and characterize temporal systematics in
interferometric data from the Hydrogen Epoch of Reionization Array
(HERA).
We begin with the Temporal Discontinuity Index and Spectral
Discontinuity Index to identify abrupt changes in signal power across
time and frequency. These metrics, combined with statistical tools,
enable improved detection of problematic antennas and reveal
associations with other systematic effects. To further improve
identification in complex cases where multiple systematics overlap, we
apply Empirical Mode Decomposition, which separates time-series data
into components associated with different temporal scales. This allows
clearer isolation of systematic features that are otherwise difficult
to distinguish. Our results demonstrate that these methods effectively
detect and characterize systematic effects, providing a framework for
antenna performance assessment. The approach is directly applicable to
HERA and scalable to future large radio interferometers.