Facade scan
Waypoints for photographing a building face: level passes at a fixed standoff, stacked up the wall with the overlap you set, and the on the facade.
Planning and education aid. Not for primary navigation. Full disclaimer
Experimental: not yet fully verified. How results are checked
Fly 1 pass of 2 photos at 30 m from the wall. Each pixel covers 0.82 cm of the facade.
| Latitude | Longitude | Height | Heading |
|---|---|---|---|
| 40.4403298 deg | -80.0017348 deg | 12.5 m | 360.0 deg |
| 40.4403298 deg | -80.0016762 deg | 12.5 m | 0.0 deg |
- Photo width on the wall
- Photo height on the wall
- Photo spacing
- Pass spacing
- Passes
- Photos per pass
Provenance
- Computed by
- drone.mission.facade 1.0.0, core 0.1.0
- Model
- Photo footprint on the wall = sensor size × standoff / focal length; GSD = pixel pitch × standoff / focal length (Wolf, Dewitt & Wilkinson 2014, ch. 6). Passes and photos: n = 1 when the span fits one photo, else ⌈(span − footprint)/(footprint × (1 − overlap))⌉ + 1, centered and evenly spaced. Stations by the geodesic direct problem along the facade, offset square to it by the standoff (Karney 2013)
- Accuracy
- Exact for a flat, vertical facade and a level camera; heights are above the facade's base, not MSL
- Notes
- 1 shown with the answer
- Cites
- Wolf, P. R., Dewitt, B. A., and Wilkinson, B. E., McGraw-Hill, Elements of Photogrammetry with Applications in GIS; Karney, C. F. F., Journal of Geodesy, Algorithms for geodesics
Something look off?
How we got thisFormula, worked example, sources, and proof
Model: Photo footprint on the wall = sensor size × standoff / focal length; GSD = pixel pitch × standoff / focal length (Wolf, Dewitt & Wilkinson 2014, ch. 6). Passes and photos: n = 1 when the span fits one photo, else ⌈(span − footprint)/(footprint × (1 − overlap))⌉ + 1, centered and evenly spaced. Stations by the geodesic direct problem along the facade, offset square to it by the standoff (Karney 2013)
Accuracy: Exact for a flat, vertical facade and a level camera; heights are above the facade's base, not MSL
Worked example: A 50 m wall, 25 m tall, from 30 m away. Source: add-drone-suite facade GSD scenario (30 m standoff). It is golden test vector v011, and every build checks the tool still gives its answer within its tolerance.
You enter
- Facade ends
- 40.4406, -80.002 40.4406, -80.001411
- Focal length
- 8.8 mm
- Image width
- 5472
- Sensor height
- 8.8 mm
- Sensor width
- 13.2 mm
- Standoff
- 30 m
- Top of the wall
- 25 m
You get
- GSD on the facade
- 0.82 cm
- Photo width on the wall
- 45 m
- Photo height on the wall
- 30 m
- Photo spacing
- 4.97 m
- Pass spacing
- 0 m
- Passes
- 1
- Photos per pass
- 2
- Photos
- 2
- Facade length
- 49.97 m
- Path length
- 5 m
Review: Not yet independently reviewed by a Part 107 remote pilot.
Last verified: 2026-09-18, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.
Status: version 1.0.0, core 0.1.0. See this tool in the verification report.
Checked against: 14 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.
Sources
- Elements of Photogrammetry with Applications in GIS, Wolf, P. R., Dewitt, B. A., and Wilkinson, B. E., McGraw-Hill, 4th edition. Chapter 6 (scale and coverage, with the object distance in place of the flying height). Read free.
- Algorithms for geodesics, Karney, C. F. F., Journal of Geodesy, Vol. 87, No. 1. pp. 43-55 (direct and inverse geodesic problems).
Terms
- GSD: ground sampling distance
- The ground width one image pixel covers, such as 2 cm per pixel. A smaller GSD shows more detail. Source: Elements of Photogrammetry with Applications in GIS
Experimental means this tool has not yet met the stable bar: at least 20 golden vectors, differential tests, and an independent worked example.
GSD — ground sampling distance
The ground width one image pixel covers, such as 2 cm per pixel. A smaller GSD shows more detail.
Source: Elements of Photogrammetry with Applications in GIS