Quarry 3D Modelling and Volume Calculation by Drone

The extractive industry — aggregate quarries, limestone, sandstone, open-pit mines — needs precise knowledge of its volumes: extracted volumes, stockpile volumes, remaining volumes to be exploited. These volume calculations have traditionally been carried out by surveyors with total stations — a slow, costly and sometimes hazardous operation on active working faces. Photogrammetric drone surveys are transforming this process: in a few hours of flight, an entire quarry is modelled in 3D with decimetre precision.

Volume requirements in the extractive industry

Monitoring extraction progress

A quarry operator must regularly track the progress of working faces to:

• Verify that extraction conforms to the approved operating plan
• Calculate extracted tonnages for billing and materials accounting
• Anticipate extraction requirements based on commercial demand

Stockpile management

Aggregate stockpiles, run-of-mine materials or processed product stockpiles represent significant financial assets. Their accounting valuation requires regular volumetric inventory. With a drone, an entire quarry's stockpiles are inventoried in half a day, with a precision of ±2 to 5% on volumes.

Studies and regulatory filings

A quarry operating authorisation application (Water Act file, impact assessment) requires an accurate topographic survey of both the initial state and the planned final state. These studies are carried out by expert surveyors, but the drone can produce the baseline topographic survey in a fraction of the time and cost.

Precision and methodology

Drone photogrammetry produces a dense 3D point cloud whose precision depends on image resolution, flight altitude and the number of ground control points (GCPs).

For quarries, standard precision is:

• Planimetry (X, Y): ±3 to 5 cm with GCPs
• Altimetry (Z): ±5 to 8 cm with GCPs
• Volumes: ±2 to 5% depending on stockpile shape and terrain complexity

This precision is sufficient for commercial volume calculations and regulatory filings, and is comparable to that of a traditional total station survey.

Deliverables

From a quarry photogrammetric flight, we produce:

• 3D point cloud (LAS/LAZ) — importable into AutoCAD Civil 3D, Revit, Leica Infinity, Trimble Business Center
• Digital Terrain Model (DTM) — ground surface without vegetation or structures
• Digital Surface Model (DSM) — overall surface including stockpiles and equipment
• High-resolution orthophoto — georeferenced aerial view usable as a GIS base map
• Volume calculation report — by defined zone, with comparison against a previous reference state
• Cross-sections and profiles — transverse and longitudinal sections of working faces

Frequency and monitoring

For operators wanting continuous monitoring, we offer monthly or quarterly survey campaigns, with an online volume evolution dashboard. This regularity allows precise tracking of extraction rates and anticipation of operating authorisation renewals.

Our field approach

The DJI Matrice 4TD is our platform of choice for quarry surveys, for its stability in moderate wind and its ability to operate in dusty environments. Our operators deploy geodetic control points (GCPs) with RTK differential GPS to guarantee the planimetric and altimetric precision of each survey.