Operational Non-identifiability of Single-epoch Low-rank RFI Mitigation: Controlled Failure-mode Analysis and HERA Evidence

Abstract

The rapid proliferation of low Earth orbit (LEO) satellite constellations has introduced a new class of radio frequency interference (RFI) that poses a fundamental challenge to modern radio astronomy. In particular, unintended electromagnetic radiation emitted by satellite electronics exhibits strong temporal variability and weak spectral regularity, limiting the effectiveness of conventional mitigation techniques that rely on long term averaging or multi epoch observations. In this work, we investigate the fundamental limits of low rank interference mitigation in the single epoch regime, where only a single time frequency snapshot is available. We formulate satellite induced interference as a structured but non stationary component superposed on astrophysical signals and thermal noise, and analyze the conditions under which low rank decomposition can successfully suppress interference while preserving underlying astronomical information. Through controlled simulations and empirical analysis, we demonstrate that aggressive rank truncation can lead to substantial signal distortion, particularly for diffuse or low signal to noise astrophysical features. We quantify this trade off using preservation and suppression metrics, and show that beyond a critical interference strength, low rank methods inevitably induce irreversible information loss. Our results clarify the operational boundaries of low rank approaches for next generation radio observations and highlight the need for interference aware, data driven mitigation strategies tailored to the single epoch regime.

arXiv comment13 pages, 7 figures

References in corpus (19)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Rank-Sparsity Incoherence for Matrix Decomposition
• Hydrogen Epoch of Reionization Array (HERA)
• Reionization and Cosmology with 21 cm Fluctuations
• A morphological algorithm for improving radio-frequency interference detection
• Bright Source Subtraction Requirements For Redshifted 21 cm Measurements
• What Next-Generation 21 cm Power Spectrum Measurements Can Teach Us About the Epoch of Reionization
• Four Fundamental Foreground Power Spectrum Shapes for 21 cm Cosmology Observations
• Post-correlation radio frequency interference classification methods
• A Sensitivity and Array-Configuration Study for Measuring the Power Spectrum of 21cm Emission from Reionization
• First Results from HERA Phase I: Upper Limits on the Epoch of Reionization 21 cm Power Spectrum
• Multichannel interference mitigation methods in radio astronomy
• Applying Deep Learning to Fast Radio Burst Classification
• Unintended electromagnetic radiation from Starlink satellites detected with LOFAR between 110 and 188 MHz
• Absolving the SSINS of Precision Interferometric Radio Data: A New Technique for Mitigating Faint Radio Frequency Interference
• Redundant-Baseline Calibration of the Hydrogen Epoch of Reionization Array
• Optimizing Sparse RFI Prediction using Deep Learning
• Deep residual detection of radio frequency interference for FAST
• Deep Learning improves identification of Radio Frequency Interference