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Deliverables Explained

Contours: intervals, datums, and CAD export

Elevation lines at the interval you choose — how they're generated and how to get them into CAD.

Contours are lines that connect points of equal elevation. DroneFlow derives them from the terrain model, so they follow the real ground, and you control the interval.

Choosing an interval

The same site contoured twice side by side: on the left a dense set of closely spaced 1-foot contour lines, on the right a much sparser set of 5-foot lines over identical ground
The same 190 m of ground, contoured twice. Left: 1 ft — every grade break shows, and a busy site gets crowded. Right: 5 ft — reads cleanly for an overview but fine grade disappears. Highland Homes, total relief 13.8 ft; brighter lines are index contours.

A tighter interval (say 1 ft) shows fine grade but crowds a busy site; a wider interval (5 ft) reads cleanly for an overview. Pick the interval that matches how the drawing will be used.

Datum matters

Contour elevations are only meaningful against a known vertical datum. DroneFlow delivers elevations as orthometric height rather than raw ellipsoidal height — which is what most site and civil work expects — on the datum you choose at upload: NAVD88 (GEOID18) in the US, or EGM2008 anywhere in the world. See coordinate systems and datums.

Getting them into CAD

Contours export as CAD-ready vectors (DXF/SHP) so they drop straight into your drawing, alongside the orthomosaic as a reference image.

Related in Deliverables Explained

Orthomosaic: what it is and how to use it

The georeferenced, distortion-corrected site image — the base layer for measuring on the map.

DSM vs. DEM: the two elevation models

Surface vs. bare-earth elevation — what each measures and which one your task needs.

3D models and point clouds

The textured mesh you orbit in the browser, and the dense point cloud behind it.

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