Speaker
Description
The recent MWA Phase III upgrade included the deployment of new receivers and a new correlator, which has significantly improved data quality for 21 cm cosmology. In particular, data taken in the new oversampled mode does not suffer major spectral contamination due to coarse channelization, making it possible to observe subtle instrumental effects that were previously difficult to isolate.
I will present ongoing commissioning work using observations from the 2025 season. I will focus on characterizing residual spectral structure arising from effects in the signal processing chain, such as cable reflections. These investigations aim to improve our understanding of the upgraded instrument response and provide the foundation for accurate calibration of instrumental systematics in future scientific analyses.