The brief
The quarry operator needed a regular, documented overview of extracted material volumes. The manual total-station surveying used previously took several days, disrupted machinery operations on site, and produced data too infrequently to be useful for accounting purposes.
A further complication was that stockpiles at a quarry are constantly in motion - material arrives and leaves between any two measurements. Without a common coordinate base, results from two different visits are not directly comparable, so the earlier data was unusable for reporting as well.
Our approach
We established a permanent network of ground control points, allowing every subsequent flight to be tied to the same coordinate system and compared over time. The aerial survey was completed in one day, producing an orthophoto and surface model from which we calculated the volume of each stockpile separately.
We planned the flight lines with 80 % image overlap so the surface model would stay dense enough even on the steep faces of the stockpiles. Volumes were computed against a fixed base surface, which lets each quarter be compared with the previous one without recalibration.
The outcome
Field work dropped from three days to one, without disrupting daily quarry operations. The client now receives a quarterly volume report accurate to 2–3 cm, with data directly comparable between periods.
A further benefit was safety: the surveyor no longer walks across stockpile slopes or inside the machinery working zone. Because the control point network is permanent, every subsequent visit costs less than the first one did.
