Home › Help Center › Deliverables Explained

Deliverables Explained

DSM vs. DEM: the two elevation models

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

DroneFlow produces two elevation grids, and using the right one matters for volumes, drainage, and design.

The same 160-metre area rendered twice: on the left the DSM, where tree canopy and houses stand up off the ground; on the right the DEM, a smooth bare-earth surface where only the graded pads and road edges remain
The same ground, both surfaces. Left: DSM — canopy and structures included. Right: DEM — bare earth. Highland Homes, 160 m across, rendered at true 1:1 vertical scale with identical lighting; the only difference is what sits on the ground.

DSM — Digital Surface Model

The DSM is the site as captured: it includes buildings, equipment, stockpiles, and tree canopy — the top of everything. Use it to measure the height of objects and the volume of stockpiles.

DEM / DTM — the bare ground

The DEM (also called a DTM) is the bare-earth surface with objects and vegetation removed. Use it for grading, drainage, and comparing against a design surface.

Which one for a volume?

A stockpile volume is the DSM (the pile) measured against a base surface — either the surrounding ground or a design plane. DroneFlow's volume and cut/fill tools handle that for you; you just draw the boundary.

Bare-earth extraction is a best-effort estimate, not a substitute for a surveyed ground shot under dense cover. Where trees are continuous, the DEM is interpolated.

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.

Contours: intervals, datums, and CAD export

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

3D models and point clouds

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

Ready to try it on your own site?

Start a free trial — no credit card required.

Start Free Trial

Still stuck? Contact us and a human will help.