Survey
UAV survey overlap and area calculator
Enter flight height, camera specs, forward/side overlap, and area to estimate GSD, footprint, photo count, and duration.
Engineering reference only. Not a basis for flight operations. Wind, terrain, turns, no-fly zones, and airspace approval are not included.
Common aircraft reference specs
Compiled from public manufacturer specs. Click a row to fill the calculator. Sensor size, actual focal length, and resolution can vary by firmware and capture mode; check the manual.
| Aircraft | Sensor (mm) | Actual focal length | Pixels | Note |
|---|---|---|---|---|
| DJI Mavic 3E | 17.3 × 13 | 12.3 mm | 5280 × 3956 | 4/3 CMOS, enterprise 20MP |
| DJI Mavic 3 Classic | 17.3 × 13 | 12.3 mm | 5280 × 3956 | Hasselblad 4/3 CMOS 20MP |
| DJI Phantom 4 RTK | 13.2 × 8.8 | 8.8 mm | 5472 × 3648 | 1-inch CMOS, mechanical shutter |
| DJI Mini 4 Pro | 9.6 × 7.2 | 6.72 mm | 4032 × 3024 | 1/1.3-inch, default 12MP |
| DJI Air 3 wide | 9.6 × 7.2 | 6.72 mm | 4032 × 3024 | Wide 1/1.3-inch 12MP |
| DJI Zenmuse P1 35mm | 35.9 × 24 | 35 mm | 8192 × 5460 | Full-frame 45MP, 35mm lens |
How overlap affects WebODM reconstruction
Forward overlap controls how many tie points adjacent frames share along the flight. For WebODM / OpenDroneMap orthomosaics and 3D models, 75%–85% forward and 65%–75% side overlap are typical. Below about 60%, sparse clouds often break and DSM/orthophotos show holes.
Side overlap ties neighboring flight lines. Too little causes seams and color mismatch; too much inflates photo count and processing time with diminishing returns. Oblique 5-way keeps similar overlap and adds four angled passes for building facades.
How is this calculated?
GSD = sensor width / pixel columns × AGL height / focal length. Use the actual focal length, not the 35 mm equivalent.
Ground footprint = height × sensor size / focal length. Effective spacing is footprint × (1 − overlap) along-track and across-track.
The area is treated as a square. One extra photo is added at each end of a line. Duration = total line length / cruise speed, excluding turns, takeoff, and battery swaps. Oblique 5-way uses nadir photos × 5 and about 4× the time.