Drone topographic survey: DTM, contour lines and orthophotos.

Topographic surveying by drone

The drone flies over the area on an automatic flight plan and takes thousands of vertical and oblique photos. Tied to control points measured by RTK GNSS, these images produce a complete 3D model of the ground, vegetation and buildings, with 1 to 3 cm accuracy.

Compared with a point-by-point survey, a drone topographic survey records the entire surface: every bank, ditch or break of slope is in the model, and new measurements remain possible after the mission.

Topographic deliverables

• High-resolution georeferenced orthophotos (GeoTIFF, JPG + TFW), ready for QGIS or ArcGIS
• DSM (digital surface model) and DTM (digital terrain model) in GeoTIFF or ASC
• Contour lines at the interval you need, in DXF
• Classified point cloud and textured 3D mesh
• Profiles, areas and earthwork volumes (CSV, XLSX, PDF)

Data is delivered in Lambert 93, Lambert CC 9 zones (CC42 to CC50), WGS 84, UTM or a local grid, with NGF-IGN69 or ellipsoidal heights.

Large areas with SmartWaypoints

For a village, a quarry or a development area, our flights are planned by SmartWaypoints, our flight planning platform: flight altitude follows the terrain for a constant resolution, overlaps are set according to the target accuracy and large areas are split automatically. Because flights can be repeated, the same site can be surveyed at regular intervals to monitor changes.

What is it used for?

• Preliminary studies for development and road projects
• Quarries and earthworks: volume calculations and stockpile monitoring
• Construction monitoring and documentation at each stage
• Surroundings of monuments and buildings, alongside a heritage survey
• Natural land, environment, risk management

What about the chartered land surveyor?

A drone topographic survey provides an accurate description of the land, but it does not replace the tasks reserved for chartered land surveyors (géomètres-experts) in France, such as boundary marking and property delimitation. It usefully complements them, especially over large or hard-to-reach areas.