ADR-0001: Canonical Split Between sampled_curve and band_spec

Status

Accepted.

Context

Official optical sensor sources do not publish the same level of spectral detail.

Some sources publish full sampled response curves. Others publish only:

• center wavelength
• FWHM
• support interval
• quality flags

Treating both as the same canonical object would either lose precision for sampled data or fabricate detail for metadata-only sources.

Decision

RSRF stores two canonical forms:

• sampled_curve for official wavelength/response samples
• band_spec for official metadata-only band definitions

Derived sampled approximations remain optional and are tracked separately as realizations.

Consequences

• ingest pipelines stay honest about source fidelity
• APIs can dispatch by content kind without hiding approximations
• QA can apply different checks to exact curves and metadata-only definitions
• downstream users can choose whether to accept realized approximations