FA-55124 / Astronomical coordinate conventions / Member archive

Interferometer baseline reversal: Complex baseline conjugation is mistaken for negation · case 04

The adapter reports an incorrect visibility while other fields remain valid.

Member previewVariant 4 · 3 implementations · 6 checks per implementation

Case contract

A visibility row reversed from antenna a,b to b,a must negate its uvw vector, conjugate complex visibility, transpose cross-hand labels, negate geometric delay, and exchange antenna-based phases. The real-valued weight is attached to a sample, not to antenna order. Output fields are defined by: antennas = [d['b'],d['a']]; uvw = [-x for x in d['uvw']]; visibility = [d['re'],-d['im']]; polarization = d['pol'][::-1]; geometric_delay = -d['delay']; phase_difference = d['pa']-d['pb']

Why this case matters

Catalog, detector, sky-coordinate, and spectroscopy adapters must preserve the association between numeric coordinates and their declared reference conventions.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
astronomical fixture 0	`{"antennas": [5, 2], "geometric_delay": -8, "phase_difference": -7, "polarization": "YX", "uvw": [-2, 3, -4], "visibility": [-10, -3]}`	`{"antennas": [5, 2], "geometric_delay": -8, "phase_difference": -7, "polarization": "YX", "uvw": [-2, 3, -4], "visibility": [10, -3]}`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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