The quality of your volume measurements depends on the quality of your flight. A few simple habits — enough overlap, full coverage, and steady conditions — make the difference between a clean 3D model and a re-fly.
The golden rules
- Overlap generously. Photogrammetry reconstructs the pile by matching features across multiple photos, so every part of every pile should appear in several images. When in doubt, take more photos — extra images are cheap; gaps are not.
- Cover everything, including edges. Fly past the edges of each pile and capture the surrounding ground, not just the pile itself. The ground around a pile is what defines its base in the model.
- Keep a consistent altitude. Pick one altitude for the whole survey and hold it. Fly high enough for a wide view of the site but low enough that the pile surface is sharp and detailed in each photo.
- Fly a grid pattern. Sweep the site in parallel passes, like mowing a lawn, so no area is missed. Many drone apps can fly an automated grid mission for you — automated missions produce very consistent overlap.
Capture the faces of the piles
A straight-down (nadir) grid captures the tops of piles well, but tall bunker walls and steep open faces can end up thin in the model. After your grid passes, add a few angled (oblique) shots of:
- The open feed-out face of each bunk or pile
- Tall bunker walls
- Any steep or overhanging sections
Conditions matter
- Light: Fly in even light — bright overcast is ideal. Harsh midday shadows or a low sun can hide detail; avoid flying at dawn or dusk.
- Wind: Calm days give sharper photos and steadier flight lines.
- Weather: Never fly in rain or fog. Wet, shiny plastic covers can also produce glare — overcast light helps here too.
- Moving equipment: Fly when loaders and trucks aren’t working the piles. A payloader parked on a pile becomes part of the 3D model.
Before takeoff
- Confirm a solid GPS lock so every photo is geotagged — photos without GPS data cause processing problems (see Troubleshoot uploads)
- Set the camera to JPG
- Clean the lens
- Check battery and memory card space
After landing
Spot-check a handful of photos on the drone or in your phone app: are they sharp, well exposed, and does the set cover the whole site? If a pile is missing or images are blurry, re-fly that area now — it’s much faster than discovering the gap after processing.
For maximum accuracy, RTK/PPK workflows and ground control points are supported but not required — see Drone and camera requirements.
Next step
Photos in hand? Head to Upload a drone flight to submit them for processing.