Survey grid (lawnmower pattern)
A serpentine mapping pattern over an area, with no-fly holes routed around, the fewest lines by default, overshoot, and an optional crosshatch: waypoints, line count, path length, turns, photo count, and flight time.
Planning and education aid. Not for primary navigation. Full disclaimer
Experimental: not yet fully verified. How results are checked
A published result changed on 2026-09-23: Image count and the survey grid (version 1.1.0) now count the way published flight planning does (Penn State GEOG 892): ⌈width / spacing⌉ + 1 lines with the outer lines on the edges, and ⌈length / photo spacing⌉ + 1 photos per line plus extra photos past each end, 2 by default (a new input; 0 leaves them out). Most areas gain a line. The Penn State block now gives its published 10 lines and 430 photos, where 1.0.0 gave 9 and 342. The superseded vectors pinned the old line counts. Changelog
Fly 4 lines for 3.02 km and about 104 photos. That takes about 5 min.
| Latitude | Longitude | Kind |
|---|---|---|
| 39.9999657 deg | -105.0006714 deg | line_start |
| 39.9999657 deg | -104.9922786 deg | line_end |
| 40.0004386 deg | -104.9922786 deg | line_start |
| 40.0004386 deg | -105.0006714 deg | line_end |
| 40.0009114 deg | -105.0006714 deg | line_start |
| 40.0009114 deg | -104.9922786 deg | line_end |
| 40.0013842 deg | -104.9922786 deg | line_start |
| 40.0013842 deg | -105.0006714 deg | line_end |
- Photos
- Path length
- Line length over the area
- Turns
- Flight time
- Line direction
Provenance
- Computed by
- drone.mission.survey-grid 1.1.0, core 0.1.0
- Model
- Lines swept on a local transverse Mercator plane, ⌈width / spacing⌉ + 1 of them centered so the outer lines reach the edges (Penn State GEOG 892), each covering its strip of the area and cut at buffered holes, joined in serpentine order; ⌈length / photo spacing⌉ + 1 photos per line plus the extras past each end; transits that would cross a hole follow its buffered boundary
- Accuracy
- Line spacing is true to within 1e-7 across a few kilometers (checked geodesically). Flight time ignores turns, climbs, and wind.
- Notes
- 1 shown with the answer
- Cites
- Abdullah, Q., Penn State College of Earth and Mineral Sciences, GEOG 892: Geospatial Applications of Unmanned Aerial Systems; 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: Lines swept on a local transverse Mercator plane, ⌈width / spacing⌉ + 1 of them centered so the outer lines reach the edges (Penn State GEOG 892), each covering its strip of the area and cut at buffered holes, joined in serpentine order; ⌈length / photo spacing⌉ + 1 photos per line plus the extras past each end; transits that would cross a hole follow its buffered boundary
Accuracy: Line spacing is true to within 1e-7 across a few kilometers (checked geodesically). Flight time ignores turns, climbs, and wind.
Worked example: A 602 m by 150 m field at 52.5 m line spacing. Source: add-drone-suite survey-grid scenario: lines run along the long axis, ⌈150 / 52.5⌉ + 1 = 4 lines.
You enter
- Area
- 40, -105 40, -104.99295 40.00135, -104.99295 40.00135, -105
- Groundspeed
- 10 m/s
- Height above ground
- 120 m
- Line spacing
- 52.5 m
- Photo spacing
- 30 m
You get
- Flight lines
- 4
- Photos
- 104
- Path length
- 3.02 km
- Line length over the area
- 2.41 km
- Turns
- 6
- Flight time
- 5 min
- Line direction
- 90°
- Height
- 120 m above ground level (constant) at every waypoint
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 1.1.0, core 0.1.0. See this tool in the verification report.
Changes
- 2026-09-23, fixed: The worked example was titled a 600 m by 150 m field, but its corners are 602 m apart along the lines, which is why it gives 22 photos a line and 104 in all. The title now says 602 m by 150 m. No results change. Changelog
- 2026-09-23, result change: Image count and the survey grid (version 1.1.0) now count the way published flight planning does (Penn State GEOG 892): ⌈width / spacing⌉ + 1 lines with the outer lines on the edges, and ⌈length / photo spacing⌉ + 1 photos per line plus extra photos past each end, 2 by default (a new input; 0 leaves them out). Most areas gain a line. The Penn State block now gives its published 10 lines and 430 photos, where 1.0.0 gave 9 and 342. The superseded vectors pinned the old line counts. Changelog
Checked against: 8 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.
Sources
- GEOG 892: Geospatial Applications of Unmanned Aerial Systems, Abdullah, Q., Penn State College of Earth and Mineral Sciences, online course text, retrieved 2026-09-23. Lesson 4, Designing a Flight Route (number of flight lines; number of images).
- Elements of Photogrammetry with Applications in GIS, Wolf, P. R., Dewitt, B. A., and Wilkinson, B. E., McGraw-Hill, 4th edition. Chapter 18 (flight planning: flight lines, photo spacing, number of photos). Read free.
- Algorithms for geodesics, Karney, C. F. F., Journal of Geodesy, Vol. 87, No. 1. pp. 43-55 (direct and inverse geodesic problems).
Experimental means this tool has not yet met the stable bar: at least 20 golden vectors, differential tests, and an independent worked example.
Learn the concept: Photo overlap and flight lines explained