Mitigating Internal Instrument Coupling for 21 cm Cosmology I: Temporal
  and Spectral Modeling in Simulations
  We study the behavior of internal signal chain reflections and antenna cross
coupling as systematics for 21 cm cosmological surveys. We outline the
mathematics for how these systematics appear in interferometric visibilities
and describe their phenomenology. We then describe techniques for modeling and
removing these systematics without attenuating the 21 cm signal in the data.
This has critical implications for low-frequency radio surveys aiming to
characterize the 21cm signal from the Epoch of Reionization and Cosmic Dawn, as
systematics can cause bright foreground emission to contaminate the EoR window
and prohibit a robust detection. We also quantify the signal loss properties of
the systematic modeling algorithms, and show that our techniques demonstrate
resistance against EoR signal loss. In a companion paper, we demonstrate these
methods on data from the Hydrogen Epoch of Reionization Array as a
proof-of-concept.
