Orthophoto · Volumes · Progress
Construction monitoring with drones
Each flight is a measurable snapshot of the site. Comparing the surfaces from two surveys, or the current one with the design surface, gives the volume moved, the actual progress and the deviations. An objective basis for site management and measurement.
What is drone construction monitoring?
Drone construction monitoring means flying the site at regular intervals and obtaining, on each flight, an orthophoto and a terrain model that can be compared with one another.
Each flight is a snapshot of the state of the works: what has been built, stockpiles, access routes, areas still pending.
Comparing the surfaces from two surveys, or the current one with the design surface, gives the volume moved, the actual progress and the deviations.
It is a tool for site management, measurement and control of subcontractors.
How we do it: flights that are comparable over time
We set up a permanent network of ground control points on site, measured with GNSS RTK in the project coordinate system.
We repeat the flight with the same plan (altitude, GSD, overlap) on every agreed date: weekly, fortnightly or by milestone.
We use photogrammetry with a metric RGB camera, and LiDAR where there is vegetation or scrub-covered slopes.
We process each flight with the same criteria so that the models are comparable.
If the client has a GIS platform, each flight is loaded as a dated layer.
Drone stockpile volumes and earthwork calculations
The volume is calculated within a defined area, the perimeter of each stockpile or zone, by integrating the difference between two compatible surfaces: same reference, same grid and same processing.
For earthworks, two surveys are compared, the previous one and the current one, or the measured surface is compared with the design surface. This measures cuts, fills, landfills and cumulative earthworks.
For aggregate stockpiles, the current surface (DSM) is compared with an agreed base surface: the original ground, the slab or a reference plane. The result is the material stored on each date.
We deliver the volume by zone, with the boundaries and the report that supports it.
What we deliver after each flight
All products are in the project coordinate system, ready to overlay on the CAD drawings.
- Orthophoto for the date
- DTM and DSM
- Contour lines of the current state
- Volume calculations by zone (between surveys or against the design)
- Profiles along the project alignments
- Progress report in PDF
Accuracy of drone volume calculations
With permanent ground control points and the same flight plan, the typical accuracy of the model is 2 to 5 cm, expressed as root mean square error (RMSE) on open ground or well-defined surfaces, in the project reference system (ETRS89 / UTM, with orthometric heights unless another reference is requested).
It depends on the sensor, the GSD, the ground control and the vegetation. The accuracy for each project is agreed in the proposal and documented in the control report. We check each flight against independent checkpoints that are not used in the adjustment, and deliver the residuals.
The error of the volume depends on the accuracy of the two surfaces and on how the base is defined. We document it in the report for each calculation.
Where the site has vegetation, LiDAR helps record the ground through its gaps. We classify the ground points and check the coverage obtained.
How much does drone construction monitoring cost?
It depends on the area of the site, the frequency of the flights and the products delivered after each one.
A monitoring plan with several flights is more economical per flight than one-off flights.
We work on construction sites and quarries in Valencia, Alicante and Castellón, and in the rest of Spain and Europe.
Questions about Construction monitoring with drones
How often should a construction site be flown?
It depends on the pace of the earthworks. The usual approach is one flight per monthly progress valuation, fortnightly in phases with a lot of movement, and one at the start as a baseline.
How are earthworks calculated with a drone?
Two compatible surfaces are compared within a defined area: the current survey against the previous one, or against the design surface. Integrating their difference by zone gives the cut and fill volume, with a report that documents it.
Can it be used to check a subcontractor's measurements?
Yes. The volume comes from measured models checked against ground control points, with an accuracy report. It is an objective basis for measurement and progress valuation.
Can the site be flown while machinery is working?
Yes. The flight does not interrupt the works. Machinery appears in the orthophoto. If it falls within the calculation area, we filter it out of the surface so that it does not alter the volume.
What if the site has vegetation or scrub-covered slopes?
It is flown with LiDAR. Multiple returns help record the ground through gaps in the vegetation. We classify the ground points and check the coverage, so that the DTM represents the ground and not the top of the scrub.
Tell us where the project is and what you need to solve
You can send us the site boundary, a plan or the specification. We will reply within one or two working days to review the scope and confirm when you can expect the proposal.