TRANSIT FTTH — BUILDINGS AND STREETS
Prepared 2026-09-10. Coordinates use the same local origin as data.json.

BUILDINGS
Google Research Open Buildings v3, S2 tile 15d.
https://sites.research.google/gr/open-buildings/
https://storage.googleapis.com/open-buildings-data/v3/polygons_s2_level_4_gzip/15d_buildings.csv.gz
License chosen: Creative Commons Attribution 4.0 International.
https://creativecommons.org/licenses/by/4.0/
Inference carried out May 2023; individual imagery acquisition dates are not supplied here.
Subset: centroid inside longitude 37.216..37.228, latitude 19.579..19.602.
Confidence >= 0.75: 2285 footprints. Confidence >= 0.849: 751 footprints.
Tile 15d published threshold for estimated 90% precision is 0.849. This is a regional estimate, not a guarantee for each building or for this neighborhood.
Changes: spatial/confidence filtering, rounding to local metre coordinates, simplified data schema and 3D extrusion. Footprints are detections, not verified occupied homes. Google Maps footprints and current imagery may differ. Colors, flat roof styling and uniform initial 4 m heights are illustrative. No facade, occupancy or floor count claims.

STREETS
© OpenStreetMap contributors, downloaded 2026-09-10.
https://www.openstreetmap.org/copyright
Open Database License (ODbL) 1.0: https://opendatacommons.org/licenses/odbl/1-0/
API area: https://www.openstreetmap.org/api/0.6/map?bbox=37.216,19.579,37.228,19.602
137 retained road sections. Open-ended way tails outside the area were removed.
Changes: clipping by retained consecutive in-area vertices, local coordinate conversion, retaining selected tags, assumed widths where absent. Asphalt shown only where tagged; neutral road colors do not establish actual surface material.
Adapted road data is available in environment.json under ODbL 1.0. Google building data in that file is separately offered under CC BY 4.0. Original FTTH project data.json is a separate dataset.

No live satellite imagery, Google Maps 3D tiles or field-verified terrain is included.