Adds a per-cell building-clutter penalty so the algorithm down-ranks
spots in built environments where buildings on multiple sides
scatter/block signal regardless of which station you're aiming at.
Penalty = max_height_within_75m / 5 dB, capped at 6 dB. Path-clearance
already accounts for buildings ON the link path; this is the
"surrounded by stuff" signal.
Phase 2/3/5 of the building-blockage support:
* Parser streams csv.gz tiles into compact records (centroid, radius,
height) — keeps RAM ~32 B per polygon, drops -1.0-height entries.
* Index buckets records into 0.01° (~1 km) grid cells in a public ETS
table for concurrent reads; max_height_near/3 and records_near/3
scan only the 9 nearest buckets.
* Loader lazily parses any cached quadkey before a Calculate so the
scorer is terrain-only when tiles aren't on disk yet.
* Rover.PathTerrain now treats each path-sample obstacle as
terrain_elev + max_local_building_height, so blocked LOS through
recent construction actually reduces clearance.
* Selecting a candidate pushes a candidate_buildings event with the
buildings near each rover→station path; the hook renders them as
height-coloured circles (yellow <10 m, orange 10-30 m, red >=30 m)
with a tooltip showing height in meters.
Calculate occasionally hung in production for ~30s. Adds per-phase
timing logs to Compute.run so the slow step is visible in pod logs,
and trims the Overpass road-proximity request to a 10s server-side
timeout / 12s receive timeout (no Req retries) so a slow road API
fails soft to no road penalty instead of stalling Calculate.
- Local prominence: each cell's elevation vs. its 8-neighbor ring
(~1.3 km radius) feeds a small additive bonus so broad hilltops
rank above isolated SRTM voxels
- Road proximity: one Overpass call per Calculate fetches drivable
ways inside the bbox; cells beyond ~0.5 km of any road get a
light dB penalty, gated off in tests
For each (rover cell, fixed station) pair, sample SRTM along the
great-circle path and add a per-link dB bonus proportional to the
rover's elevation above the highest intermediate terrain. Rover spots
on hilltops with clear sight to multiple stations now rise to the top.
Also vendor Leaflet's layers control PNGs and copy them under
priv/static/assets/css/images/ on build so /rover stops 404'ing on
layers-2x.png.
