# Belmont · Lincolnshire — source and method notes
Prepared 14 October 2026. 6 km radius, 12.3 km square data envelope.

## Structure and evidence
Belmont combines a tubular lower shaft and lattice upper structure. It was shortened in 2010; the older 387.7 m figure is not used in this model. Source precision varies: 351 m, 351.65 m and 351.7 m. The model uses 351.65 m as a nominal envelope, not a surveyed result.
Source: https://www.lars.co.uk/2019/02/14/belmont_transmitter/
Model origin WGS84 latitude/longitude: [53.3358528, -0.171975]. Nominal public map position, not surveyed mast base. Height 351.65 m is a nominal exterior envelope.
Guys and anchors, lattice widths, section transitions, ladders, platforms, dishes and casings are simplified research geometry. Radio aerial centres follow the archived Ofcom data where available, but mesh forms do not establish current occupancy. No engineering or operational conclusions should be drawn.

## Landscape
Tilezen/Mapzen regional elevation resampled to 25 m. Resampling does not increase native accuracy. DEM origin 126.34 m; not corrected to published station elevation. Source URLs, tile headers and hashes are under research/ten/belmont/terrain-sources.json.
OSM snapshot 14 October 2026 via standard OSM map API. Buildings use tagged height or levels × 3 m, otherwise assumed 7 m, capped at 100 m. Woodland uses assumed 10 m context clusters. Simplified polygons omit courtyards. London uses distance-based building detail for mobile performance, documented in meta.json where applied. Unavailable OSM bounding boxes: 0; exact extents are in meta.json. 
Regional terrain and displayed geometry are separate: surface and vegetation grids are entirely unknown. LOS is terrain-only, not an all-clear radio link. No RF, Fresnel, curvature or refraction.

## Services
Ofcom radio and TV workbooks retrieved 3 October 2026. Main FM, DAB and PSB/COM plan rows are retained. Caldbeck includes its separate Scottish-service row. Absence from these workbooks is not proof that no other services exist. Skelton is not represented as a television/mobile mast.

## Attribution
© OpenStreetMap contributors, ODbL: https://www.openstreetmap.org/copyright
Terrain: https://registry.opendata.aws/terrain-tiles/ ; Copernicus EU-DEM, USGS SRTM/GMTED, NOAA ETOPO as applicable. Full credits: https://github.com/tilezen/joerd/blob/master/docs/attribution.md
Ofcom information under OGL v3.0. Three.js MIT (THREE-LICENSE.txt). Reference photos remain on their original source sites.