Physical Heliacal Visibility Phase 2 Checkpoint

Date: 2026-07-30 Status: historical implementation checkpoint; Phase 2 is now closed

Final receipt: PHYSICAL_HELIACAL_VISIBILITY_PHASE2_CLOSURE_2026-07-30.md

Boundary

This checkpoint covers Python spectral single-epoch truth only. It does not activate the Phase 3 event solver, Phase 4 environmental expansion, Phase 5 root/facade/REST parity, native parity, automatic data acquisition, or runtime radiative-transfer execution.

The physical data pack remains an explicit caller-supplied local path. The engine does not search for, download, generate, or silently substitute a pack. All legacy visibility policies and call paths remain separate.

Implemented

• exact validation of the installed compatibility contract, root manifest, semantic pack version, engine contract, payload inventory, file sizes, per-file SHA-256 values, notices, provenance, and declared source artifact;
• no-extrapolation interpolation of photopic/scotopic directional twilight luminance and 400-bin direct spectral extinction;
• maximum-contributing-corner solver uncertainty plus maximum, p95, and storage error receipts;
• CIE MES2 fixed-point adaptation with a bounded same-equation bisection fallback;
• Crumey equations 28 and 34 with fixed F=2 and explicit published background domain;
• measured total directional background precedence, fully qualified SQM transformation, modeled twilight plus source-owned dark-sky anchor, and visibly coarse explicit Bortle fallback;
• rejection of background double counting;
• response-weighted photopic and scotopic target transmission;
• typed evaluated-clear, not-applicable, missing-dependency, and out-of-domain results with component, atmosphere, validity-domain, observer, background, target, threshold, and data-pack receipts; and
• an additive owning-module physical_visibility_assessment() path that does not alter visibility_assessment().

At this checkpoint, Moira owned the first-candidate planetary magnitude identity: mallama_hilton_2018_moira_planetary_v1. A caller cannot relabel that calculation. Caller input is limited to source-identified spectral response weights for the requested target. The closure subsequently removed that temporary caller-profile surface and made all first-candidate planetary profiles pack-owned.

Observer Protocol Correction

The admitted identifier is:

known_location_directed_averted_observation_v1

The target location is known and attention is directed, but the visual task is averted/peripheral after adaptation to the immediate directional field. This correction was made before public contract parity because CIE TN 007:2017 clause 6 does not admit MES2 for a foveal task.

Exact Source Receipts

Source	SHA-256	Admitted use
Crumey 2014 arXiv PDF	fa6ef183f9402be4d321bff5fa2c112510f89ca683b534e33c63fdb6538e50a4	Equations 28 and 34
CIE TN 004:2016 PDF	a549fcf5f98ae5fdd959b331dbb91eae99f5fd397bd288ad6b59c43723a4494f	MES2 equations and quantities
CIE TN 007:2017 PDF	efdd11f4bdf7d77ab3b1fb8e6b94ac89599521eba7425e474bbc82cf34c7877a	Official worked examples and task restriction
Tousey-Koomen 1953 public page	4e50f748c6c0de310ceeadcbbcd0a6626a3fccd74fe1063f9cc91640ad3212ef	Independent eight-row threshold check

The source-owned equation fixture is tests/fixtures/physical_visibility_phase2_equations_v1.json.

Data-Pack Runtime Receipt

The exact Phase 1 pack was loaded through the new public orchestration path on Windows from its explicit local directory:

pack_id: moira-physical-heliacal-visibility
version: 1.0.0
manifest_sha256: 49ac2b68ea105a8e055b27e8d4d70f6cbfe9533f971ef5e6000f0bdd95d6771b

The deterministic smoke geometry was target true altitude 5 degrees, solar center altitude -6 degrees, and relative solar azimuth 60 degrees. It returned evaluated_clear_sky, seven component receipts, an in-domain validity receipt, and a visibility margin of -1.944806269496668 magnitude. The uniform target spectrum used in this smoke was test-only evidence and is not an admitted planetary profile.

Verification

• 62 Phase 2 loader, equation, composition, public-orchestration, failure, boundary, provenance, error-envelope, and pickle round-trip tests pass.
• Ruff passes on the Phase 2 implementation and test files.
• The focused legacy selection passes 181 tests after deselecting the same two pre-existing resource-mocking failures.
• The two remaining legacy failures are:
  • lunar Yallop event fixture does not provide an active planetary kernel for the later assessment call; and
  • fixed-star not-found fixture mocks planet_at but not the newer Sun sky_position_at resource path.
• Neither failure enters a Phase 2 file or indicates a changed legacy default.

Gates Open At This Checkpoint

All checkpoint gates are now closed:

• pack version 1.1 owns source-locked profiles for Mercury, Venus, Mars, Jupiter, and Saturn;
• an independent validator rederives the target payload from exact local source receipts without importing the builder or engine;
• JSON-safe and immutable pickle round trips pass without activating Phase 5;
• both incomplete legacy resource fixtures were repaired at their test boundaries; and
• the final closure receipt records the exact pack, test, and documentation evidence.