# QA summary — KTEB vector map vs FAA source data

NASR cycle: **2026-07-09** (28-day subscription, effective 2026-07-09).

## Runway geometry constructed from FAA NASR (authoritative)
| Runway | Published length | Geodesic length of our geometry | Delta | True bearing |
|---|---|---|---|---|
| 01/19 | 6997 ft | 6996.9 ft | -0.1 ft | 3.2° |
| 06/24 | 6014 ft | 6014.1 ft | 0.1 ft | 48.2° |

## Independent cross-check: OSM runway centerlines vs NASR ends
| Runway end | Offset (m) |
|---|---|
| 1 | 1.0 |
| 19 | 0.3 |
| 6 | 0.9 |
| 24 | 1.6 |

## Method
- Runway polygons, centerlines and displaced thresholds are constructed directly from
  FAA NASR runway-end coordinates and published widths (cycle 2026-07-09), so runway
  geometry is authoritative by construction; the table above verifies the geodesic length
  of the constructed geometry against the published length.
- Taxiway/apron/building geometry from the OSM extract was visually verified against
  Esri World Imagery and the FAA airport diagram (d-TPP) at 1:1000; the independent
  OSM-vs-NASR offsets above bound the extract's positional quality at the runway ends.

## Known gaps (stated, not hidden)
- Hold-position markings and some service-road/ramp edges are not in the OSM extract; production digitizes them from FAA ADIP (AC 150/5300-18B) + high-res imagery.
- Taxiway polygons are nominal-width buffers of centerlines (75 ft); production uses surveyed pavement edges.

## Feature counts
```
{
 "runways": 2,
 "runway_centerlines": 2,
 "displaced_thresholds": 2,
 "taxiways": 48,
 "taxiway_centerlines": 75,
 "aprons": 4,
 "islands": 1,
 "blast_pads": 3,
 "buildings": 29,
 "airport_boundary": 1
}
```