DIGITAL SURFACE MODEL

DSM Software for Digital Surface Models

STREAM is DSM software that opens Digital Surface Models — the top surface including buildings, canopy and structures — and lets you measure, compute volumes and analyze them like any elevation grid, straight from GeoTIFF or a point cloud.

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What is a DSM (Digital Surface Model)?

A Digital Surface Model (DSM) represents the top of everything on the ground — terrain plus buildings, trees and other objects. It differs from a DTM (bare earth) and is often what you get first from photogrammetry or LiDAR.

DSMs are ideal for volumes of piles and structures, line-of-sight and canopy work. STREAM builds a DSM from all points of a cloud, or opens one directly.

DEM / DSM / DTM — Three different surfaces of the same terrain — which one to use, at a glance. — DEM / DSM / DTM
Three different surfaces of the same terrain — which one to use, at a glance.
**DSM — top surface** — includes buildings, trees and structures
**DTM / DEM — bare earth** — real ground with objects removed
**Objects** — present in the DSM, absent in the DTM
**Difference = object height** — building/tree height comes from this gap

DSM Software in STREAM

Open or build a DSM

Open a DSM from GeoTIFF, or build one from all points of a LAS/LAZ cloud on import.

Volumes on the surface

Measure stockpile and cut/fill volumes on the surface model, above buildings and piles.

Surface analysis

Run slope, viewshed, line-of-sight and sun & shadow on the DSM — where the top surface matters.

Compare with a DTM

Use a DSM alongside a bare-earth DTM to separate objects from terrain.

How to work with a DSM in STREAM

1
Load the surface model
Open the DSM GeoTIFF, or build one from all points of a LAS/LAZ cloud during import.
2
Confirm the coordinate system
Check the CRS as the layer is added so the DSM aligns with any DTM or orthophoto already loaded.
3
Inspect in 3D
Switch to the 3D view to see buildings, vegetation and structures standing on the surface.
4
Compare against bare earth
Put the DSM alongside a bare-earth DTM; the difference between the two is the height of everything sitting on the ground.
5
Measure or export
Take heights and profiles directly off the surface, and export the result as GeoTIFF when it goes back to GIS.

Supported formats

GeoTIFF

DSM elevation raster

LAS / LAZ

Point cloud STREAM turns into a DSM (all points)

Frequently asked questions

What is the difference between a DSM and a DTM?

A DSM (Digital Surface Model) includes buildings and vegetation — the top surface. A DTM (Digital Terrain Model) is bare earth. STREAM opens and builds both.