Adds Microwaveprop.Propagation.AsosNudge: a pure IDW bias-field module
that takes ASOS observations + HRRR profiles and returns re-scored grid
rows for every cell within 250km of a reporting station. Upper-air
fields (min_refractivity_gradient, pwat_mm, hpbl_m, profile, duct
metadata) pass through unchanged so HRRR's signal isn't clobbered.
The old AsosAdjustmentWorker was unwired and buggy — nil'd out ~22% of
the scoring weight and wrote orphan timestamps. Replaced with a slim
worker that queries the latest HRRR valid_time, fetches live ASOS
currents, calls AsosNudge.compute/3, and upserts onto
(lat, lon, valid_time, band_mhz) so nudged values overwrite the HRRR
hour cleanly instead of polluting available_valid_times. After each
upsert it warms ScoreCache and broadcasts propagation:updated so live
/map clients refresh.
Cron hooked up every 10 minutes in config.exs and dev.exs. Also cleaned
up the stale "dev has propagation disabled" note in CLAUDE.md.
13 new AsosNudge unit tests cover: residual computation (co-located,
out-of-grid, nil fields), IDW weighting (single station, far station,
two equidistant stations, nil component handling), upper-air
preservation, and the compute/3 entry point's shape and radius filter.
Drive-by Styler formatting touched a handful of unrelated files from
`mix format`.
- ScoreCache stores {band, valid_time} as %{{lat, lon} => score} map so
point lookups are O(1); adds fetch_point/4 and valid_times/1
- available_valid_times/1 reads directly from ScoreCache when warm,
falls back to DB on cold start
- point_forecast/3 iterates cached valid_times and uses fetch_point/4
instead of hitting the DB per click
- NexradCache: node-local ETS cache of decoded n0q PNG pixel buffers
keyed by 5-minute rounded timestamp; skips ~1-5s HTTP+decode on
concurrent/repeat clicks within the same window
- MapLive: start_async the rain_scatter fetch so point_detail renders
immediately with a pending marker; push rain_scatter_update when
NEXRAD resolves
- MapLive: preload all 18 remaining forecast hours for the current
viewport after mount/band change/propagation_updated; client caches
them and renders timeline scrubs instantly without a server roundtrip.
Adds set_selected_time event for fast-path state sync.
- Propagation map JS: forecastCache map + drawScatterMarkers helper,
timeline click uses preloaded cache when available
When clicking a grid point, fetches the latest NEXRAD composite
reflectivity and identifies rain cells within 300 km that could
enable rain scatter contacts. Shows:
- Scatter classification (excellent/good/marginal/none)
- Top 3 cells with dBZ, distance, bearing, and relative signal
- Colored circle markers on the map at rain cell locations
- Markers sized by reflectivity, colored by intensity
Uses simplified bistatic radar equation accounting for reflectivity,
frequency-dependent scattering (Rayleigh/Mie), and R^4 path loss.
NEXRAD cells sampled every ~5 km within bounding box for efficiency.
