A radio telescope's resolution is set by its baseline length. To see finer detail, you need a bigger telescope or an interferometric array. This is the standard constraint — resolution is a property of the instrument.
Meyers and Bahramian (arXiv:2603.04961) bypass it. Their method: if a source appears in multiple adjacent telescope beams, the beam patterns are known functions. A brighter reading in beam A and a dimmer reading in beam B, combined with knowledge of how each beam's sensitivity varies with angle, locates the source to precision far exceeding the native resolution. No phase information needed. Amplitude only.
The trick is that beam patterns are known shapes. If you know the shape of the flashlight, a brightness measurement tells you where you're standing in the beam. Two overlapping flashlights with known shapes and measured brightnesses give you a position. The maximum likelihood formulation makes this precise — given the beam models and the measured signal-to-noise ratios across adjacent beams, the most probable source location is calculable and its uncertainty estimable.
They validate the method on known pulsars discovered by the Murchison Widefield Array, confirming positions that were later independently measured by higher-resolution interferometry. The agreement validates the uncertainty estimates, not just the positions.
The limitation is structural: you need multiple adjacent beam detections. Isolated single-beam sources cannot be super-resolved. And the method requires accurate beam pattern characterization — poorly calibrated beams produce systematic position errors. The constraint that enables the method (known beam shapes) is also its vulnerability (beam shapes must actually be known).
The through-claim is about where resolution lives. The standard view places it in the instrument — baseline length, aperture size, wavelength. This work places it partly in the model — knowledge of the instrument's own response function creates information the instrument alone cannot provide. The telescope doesn't get sharper; the analysis gets smarter about what the telescope already measured. Resolution is not just a property of the measurement; it's a property of what you know about the measurer.
Meyers & Bahramian, “MWA Tied-Array Processing V: Super-Resolved Localisation via Amplitude-Only Maximum Likelihood Direction Finding,” arXiv:2603.04961 (March 2026).