The layer compared the server's fetchedAt with the browser's clock, so a
skewed client clock could shift or void the 30-minute window. The proxy now
returns ageMs (its own now minus fetchedAt, at serve time, on fresh, cached
and stale answers); the source refuses a snapshot without a finite,
non-negative ageMs, and the layer dates rows as its now() - ageMs. fetchedAt
stays in the payload for display.
Tests: proxy cached/stale answers report ageMs on the server clock; the
source rejects missing/invalid/negative ageMs; the layer replay test drives
ageMs. qa-gnss stubs send ageMs.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Re-enabling after a disable longer than the window no longer shows the
old cells until the next refresh. A healthy report arriving 31 minutes
after a degraded one, with no prune in between, starts clean; exactly
30 minutes still counts.
Maintainer review on #855 (mazy1998, 2026-10-06):
- records: presence (seenAt) and degraded evidence (degradedAt) age
separately, so continuing healthy reports no longer keep an older
degraded flag alive past 30 minutes; an aircraft returning after the
window starts fresh. pruneGnssObservations ages the store with no new
rows.
- Rows are dated by the snapshot's fetchedAt, which the proxy keeps on
cached and stale answers: a replay never restarts the window, the
proxy stops serving a stale snapshot older than the window, the source
refuses an undated one, and cells expire during fetch failures and
while there is no view anchor.
- Normalization accepts ADS-B versions 1 and 2 only; a missing, invalid
or negative seen_pos is not a confirmed position from the last minute.
- qa-gnss: keyboard, 390x844 viewport (fresh page: isMobile reloads) and
replay-age sections; the live cell assertion bins the returned rows
with the layer's own rules instead of a raw row count.
Review on #855: the per-aircraft rule (NIC < 7 || NACp < 8, borrowed from
the US 14 CFR 91.227 ADS-B Out minima) is GEV-defined, not gpsjam's, and
gpsjam's map shows low navigation accuracy, not necessarily jamming.
- Primary cell state is now `navigation-integrity-anomaly` (medium/high) or
`nominal`; `suspected-gnss-interference` is a secondary `interpretation`
marked validated: false.
- GNSS_PROVENANCE / gnssProvenance({ windowMs }) records the classifier
(gev-nic-nacp-v1, GEV, unvalidated), the gpsjam aggregation (formula,
bands [0.02, 0.1], FAQ source) and the GEV 30-minute visited-view window,
built from the constants the code applies. Exposed as layer.provenance
and getStats().provenance; the proxy tags responses with `classifier`.
- Visible name "GNSS Integrity", legend "... low accuracy", blurb leads with
low navigation accuracy and states the threshold is a GEV choice.
- Layer id `gnss-interference` and share token `0` unchanged.
- Voice aliases add "gnss integrity", "navigation integrity",
"low navigation accuracy"; the interference aliases stay.
- Docs describe the method as GEV threshold + gpsjam aggregation.
- Tests: provenance object, renamed state/label, proxy classifier tag;
qa-gnss asserts provenance and wording in the real app.
Hex project - Crew Leo Agile dev team.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
- Route the adsb.lol GNSS source through createReferenceSources and the
constructCatalog contract; app layer module is a thin pass-through.
- Describe the method honestly: gpsjam.org's published cell formula and
bands; per-aircraft thresholds are the 14 CFR 91.227(c) ADS-B Out minima
(NIC < 7, NACp < 8) plus readsb gpsOkBefore.
- Proxy: reuse the adsb.lol anchor parser, honour upstream Retry-After
(clamped 5-120 s), serve stale during cooldown, cap the body size.
- Layer: redraw only when a cell id or band changes, treat a settling
camera as a retry rather than a rejected enable, keep low cells visible,
skip rows without finite coordinates, state the 3-aircraft rule in the
legend blurb.
- Voice: gnss-interference in set_layer_visibility / show_data_layers_menu
plus common aliases; voice pins re-derived.
- qa-gnss: stub the route in-page (request interception stalls Cesium's
geometry workers), assert every cell is built, cover all bands over land
and sea, screenshot every state with the Data Layers row open.
Hex project - Crew Leo Agile dev team.
Co-Authored-By: Claude <[email protected]>
Bins airborne ADS-B v1/v2 aircraft that report degraded navigation
integrity (NIC < 7, NACp < 8, or readsb's GPS-loss flag) into 0.5 degree
cells over a rolling 30-minute window, coloured with the gpsjam.org
bands. Keyless: reads the capped adsb.lol point snapshot around the view
through /api/gnss-integrity, which returns integrity fields only, caches
60 s per whole-degree anchor, backs off on upstream 429 and serves the
last snapshot on failure. Adds scripts/qa-gnss.mjs.
Built by the Hex project (Crew Leo Agile dev team).
Co-Authored-By: Claude <[email protected]>
Mazeyar Moeini Feizabadi