Both retired in light of the 2026-04-25 revision report
(`docs/algo-reports/2026-04-25-algo-revisions.md`):
* HPBL boundary-layer multiplier in `Scorer.score_refractivity/{3,4,5}`
is gone. On the n=47,418 10 GHz HRRR-matched corpus rho_hpbl is
+0.004; binned distance is flat to within ±5 % across 200–2,000 m.
The previously reported 2.3× ratio between shallow and deep HPBL
bins was a small-corpus artefact that disappeared once the matched
corpus passed ~5,000 contacts.
* Native-profile 1.15× duct boost is gone. At 10 GHz on n=52,341
matched contacts, cells where `best_duct_band_ghz` ≥ band ran
*shorter* than no-duct cells (198 km vs 211 km, n=173 vs 44,658).
The Bulk Richardson gate that existed only to suppress that boost
in turbulent conditions is also retired; arity preserved on every
`score_refractivity` overload so callers compile unchanged.
Same retirements applied in the Rust port (`rust/prop_grid_rs/src/scorer.rs`)
to keep the Elixir/Rust parity tests green.
algo.md updated end-to-end:
* Finding 4 (HPBL) rewritten to "no usable signal" with the
n=47,418 bin table.
* Finding 5 (gradient) tightened: load-bearing only at 24 GHz,
set band-specific gradient weight to 0 outside [10, 47] GHz on
the next derive_band_weights run.
* Finding 8 (time-of-day) augmented with the robust hour-bucketed
amplitude index (40 / 82 / 101 % at 10 / 24 / 47 GHz) and a
selection-bias caveat for VHF/UHF (where 129–148 % amplitude
reflects evening contest scheduling, not propagation).
* Finding 9 (sounding) refreshed against the n=27,058 corpus.
* Part 2c "Native-profile duct boost" rewritten as
"retired 2026-04-25" with the falsifying join.
* Part 2c "Commercial-link inverse sensor" promoted from deferred
with the 22-day, 38k-sample SNMP corpus, the +0.61 / −0.61 PWAT
and pressure correlations against the 37-hour HRRR overlap, and
the 04–05 / 10–12 local two-peak morning fade window.
* Part 2b "Pressure" annotated with the U-shape at 10 GHz and the
next-iteration target.
* Part 2d "What stayed, what left" + "Open items" updated to
reflect the four code/doc moves.
119 Elixir scorer tests green, 134 Rust scorer tests green, 2,888
total Elixir tests + 221 properties green via `mix precommit`.
Extracts the memory-hostile HRRR fetch → decode → score pipeline for
forecast hours 1–18 into a separate Rust service (`prop-grid-rs`).
Elixir retains f00 with its native-duct + NEXRAD + commercial-link
enrichment; Rust handles the other 18 steps per hourly chain.
Hand-off via a new `grid_tasks` table (`FOR UPDATE SKIP LOCKED` claim
from Rust, Postgrex `NOTIFY propagation_ready` back to Elixir). Rust
writes the same on-disk score-grid format Elixir already uses, to the
same `/data/scores` NFS tree. Phase 1 ships in shadow mode with
PROP_SCORES_DIR=/data/scores_shadow.
Rust crate layout at `rust/prop_grid_rs/` (1:1 module parity with the
Elixir source it ports):
- grid, region, band_config, scores_file, sounding_params
- scorer: all 10 factors + composite. Matches the Elixir scorer
byte-for-byte across 115 golden-fixture samples (5 scenarios
× 23 bands).
- decoder: wgrib2 subprocess + Fortran-record lola-binary parser
- fetcher: HRRR URL derivation + idx cache (1h TTL) + 8-way
parallel byte-range downloads with 429/5xx retry
- pipeline: end-to-end chain step, f00 rejected at the boundary
- db: sqlx grid_tasks claim/complete + propagation_ready NOTIFY
- bin/worker: tokio main loop, JSON logs, SIGTERM-safe
91 Rust tests + clippy -D warnings clean. 2,158 Elixir tests green.
Elixir additions:
- `GridTaskEnqueuer` seeds fh=1..18 rows from
`PropagationGridWorker.seed_chain/0`
- `NotifyListener` LISTEN → warm `ScoreCache` → PubSub fan-out
- `ShadowComparator` diffs prod vs shadow `.ntms` bodies
- `mix rust.golden` task writes the Rust-side golden fixture
k8s: new `deployment-grid-rs.yaml` pinned to talos5 (32 GB NUC) via
`prop-grid-rs=primary` nodeSelector + `workload=grid-rs:NoSchedule`
toleration, 512 Mi limit, sharing the existing NFS `/data` mount.
The plan document is at `plans/vivid-hatching-quail.md` (local to my
workstation); phases 2 (cutover) and 3 (talos5 concurrency tuning)
follow after 72h of shadow-mode parity.
