FA-55157 / Astronomical coordinate conventions / Member archive

Interferometer channel uvw: Adjacent channel phase advance uses absolute channel frequency · case 02

The adapter reports an incorrect channel phase step while other fields remain valid.

Member previewVariant 2 · 3 implementations · 6 checks per implementation

Case contract

A reduced visibility coordinate adapter supplies speed constant c, channel frequency f, reference frequency fr, physical baseline b, and delay tau. Wavelength uvw scales as b*f/c. Angular fringe rate is represented in cycles, not radians. Frequencies and c are positive. Output fields are defined by: channel_uvw = d['b']*d['f']/d['c']; physical_baseline = d['b']*d['f']/d['c']*d['c']/d['f']; phase_cycles = d['tau']*d['f']; channel_phase_step = d['tau']*d['df']; time_phase_step = d['rate']*d['dt']; frequency_jacobian = d['b']/d['c']

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	`{"channel_phase_step": 16, "channel_uvw": 6.5, "frequency_jacobian": 0.8125, "phase_cycles": 16, "physical_baseline": 13.0, "time_phase_step": 10}`	`{"channel_phase_step": 6, "channel_uvw": 6.5, "frequency_jacobian": 0.8125, "phase_cycles": 16, "physical_baseline": 13.0, "time_phase_step": 10}`	Failed

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

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