Accuracy is a contract, not a camera spec
Every mapping proposal quotes a number — 2 cm, 5 cm, "survey-grade." But accuracy doesn't live in the drone. It lives in the whole system: flight height, overlap, lens calibration, ground control, and independent verification. Change any one and the number moves.
When we promise 2 cm, we mean this: checkpoints surveyed independently of the control network agree with the map within about two centimeters, horizontally, at 95% confidence. If a provider can't describe their checkpoints, their number is decoration.
The three levers that matter
Ground sampling distance (GSD). Lower flight means smaller pixels and finer detail — but more images, longer flights, and heavier processing. Most engineering work lands between 1 and 3 cm GSD. Finer than that buys you prettier zoom, not better decisions.
Ground control points (GCPs). Surveyed targets that pin the imagery to real coordinates. Without them, even a perfect flight drifts by meters. With five to ten well-placed GCPs, consumer-grade drones produce professional maps.
Checkpoints. The honest part: points measured but never fed to the processing, used only to score the result. Always ask for the checkpoint residuals in writing.
How to specify what you need
- Concept and planning: no control needed, meter-level is fine, fastest and cheapest.
- Design and engineering: GCP-controlled, checkpoint-verified, 1–5 cm class with residuals reported.
- Legal boundaries: drone maps support but don't replace licensed boundary survey — ask your surveyor how the two combine.
The question to ask any provider
Not "what drone do you fly?" but "what were your last checkpoint residuals, and can I see them?" A good answer comes with numbers. Ours always does — every Skyvane mapping delivery includes the accuracy report, not just the map.