NODEDC_MISSION_CORE/docs/adr/0027-e34-short-ttl-occupied-unknown-layer.md

ADR 0027 — E34 short-TTL occupied/unknown temporal layer

Date: 2026-07-27

Status: accepted for source-scoped diagnostic/shadow use

Context

E32 published exclusive, source-indexed PointSlab ownership over all 4,489 immutable RAVNOVES00 frames. E33 proved that the exact E32 publication stream can be delivered at recorded 1.0× pace through bounded worker channels with closed accounting. Neither result is a local temporal model: geometry-only component keys are frame-local, current support disappears immediately when a source is unavailable, and there is no explicit expiration event.

The K1 stream is already registered mapped evidence. It does not retain the beam origin and firing time required for honest ray-cleared free-space mapping. The accepted persistent reconstruction must also remain a separate, immutable derivative.

Predeclared decision

1. E34 consumes only the accepted content-addressed E32 result under the accepted E33 timing/accounting envelope. It never rewrites E32, E33, raw evidence, the mapped stream or persistent reconstruction.
2. The output is a separate lidar-local-map/v1 diagnostic derivative in the E32 map frame. It publishes only hit-backed occupied and conservatively aged unknown state. It never publishes free.
3. Current E32 point owners become current/occupied temporal components. Camera track identity is retained only as source provenance. Geometry-only components receive new temporal IDs and may be spatially re-associated without inventing a semantic class.
4. A component without current accepted points becomes held/unknown for at most 0.75 s. Its last hit-backed cells remain explicitly stale evidence, not current measurement and not free-space proof.
5. After the TTL, the component emits one expired/unknown tombstone and is removed from the active occupied layer. Expired cells are never published as occupied.
6. Geometry-only re-association is deterministic, one-to-one and bounded to a 0.35 s gap and 0.9 m centroid distance. It additionally requires either a 0.05 neighbor-expanded voxel overlap or a centroid distance no greater than one 0.45 m voxel.
7. The layer uses hit-only 0.45 m voxels, at most 4,096 cells per component and at most 256 active components. Crossing a bound fails closed; cells are not silently truncated and components are not silently evicted.
8. A map-frame jump candidate is diagnostic only. It requires at least four adjacent matched components within 0.25 s, median displacement of at least 1.5 m and 25th-percentile displacement of at least 0.9 m.
9. Acceptance requires complete 4,489-frame accounting, exact upstream artifact identity, bounded state, no free-space publication, no component held past TTL, expiry no later than one 0.25 s observation interval after the theoretical deadline and zero global map-frame jump candidates.
10. Continuity, re-association, geometry-only persistence and ghost lifetime are measured and reported. They are not converted into detector accuracy or ground truth and are not retuned after inspecting this run.
11. Dynamic class, traversability, planner input, commands, navigation and safety authority remain unavailable.

Consequences

• The E34 result can prove a bounded temporal contract without claiming free-space quality or changing persistent mapping.
• Camera-only, conflict, unknown and source-unavailable inputs can preserve uncertainty but cannot create new occupied cells without prior accepted hit-backed provenance.
• A rejected run remains immutable evidence. Any later profile change requires a new ADR decision, profile identity and LAB result rather than overwriting E34.

Execution outcome

The first immutable implementation result e34-temporal-occupied-1bab293c1867100e172923b189f8273c47eacca3dd179fd54573200906affd7c was rejected without changing the profile. It exposed two implementation-level architecture errors:

• scalar nearest-neighbor displacement was not sufficient to call a jump global; the corrected detector requires one coherent translation within the already fixed voxel residual;
• frame-driven expiry could not meet the TTL across a recorded 0.333 s source gap; expiration now uses an independent logical layer deadline and retains the later replay materialization time separately.

The accepted result is e34-temporal-occupied-8d9abb3f2cc072cfdbb16cc4e55798e05c35a0abe0b8f691096770e091573a73. It processes all 4,489 frames and all 2,119,302 E32 point rows, peaks at 37 active components and 324 cells per component, emits zero free cells, meets the 0.75 s TTL exactly and reports zero coherent global map-frame jump candidates. A8 now continues with E35 deterministic degradation/recovery.