BASEMAP AND DEM
Download a DEM and a Topographic Basemap Inside the Software
Before you have a survey, you still need ground to plan on. STREAM downloads the elevation model or the topographic map of your site straight into the project: draw the area, pick a source — Copernicus GLO-30 or GLO-90, AWS Terrarium, or OpenTopography with your own key — and the model arrives as terrain, clipped to your area and placed in the project coordinate system. Slope, hydrology, sun and shadow and volumes then run on it like on any other DEM.
What is a DEM download, and when is it enough?
Global elevation models are public datasets that cover the whole land surface on a coarse grid. Downloading one for your area gives you terrain to look at, to run analysis on and to plan against on day one — long before a drone or a LiDAR flight has produced a survey.
Be clear about what it is: a global model is a surface model on a coarse grid, so buildings and vegetation are part of it, and its vertical accuracy is metres, not centimetres. It is the right input for site selection, context and early studies. A quantity that will be paid for — a stockpile, an earthwork volume — needs a survey, which is what STREAM then opens.
DEM Download Software in STREAM
Terrain for an empty project
In an empty project, draw the site and select it; the download is clipped to that area and arrives as terrain. You start analysing the land before any survey exists.
Four elevation sources
Copernicus GLO-30 and GLO-90, AWS Terrarium, and — with your own key — OpenTopography with ALOS, NASADEM or SRTM. You choose the source that suits the site and the study.
Only the area you need
If an area is selected on the map, only its extent is downloaded; otherwise the extent of the data you already have is used. No continent-sized files for a ten-hectare site.
Placed in the project coordinate system
The downloaded model is placed in the project system and added to the project, so it lines up with your survey data, your CAD drawings and every measurement you make on it.
An online topographic basemap
OpenTopoMap — or your own XYZ tile service — can sit under your data as a 2D basemap, for orientation and for the printed sheet. It is clipped to the selected area or the data extent.
A cache, not clutter
Downloads stay in a cache so the same area does not download twice, and the window's Clear Cache button frees the space when you want it back.
Clear about being offline
Downloading needs a connection, and when there is none STREAM says so plainly instead of failing silently. Everything else in STREAM keeps running offline.
Attribution where it is read
The source attribution is printed on the map sheet and in reports, so data that came from a public source is credited wherever the result is handed over.
Licence-safe by design
The built-in basemap is OpenTopoMap only; other providers' tiles are not built in because of their terms. If you hold a tile service whose terms allow it, add it as your own XYZ source.
A DEM like any other
Once downloaded, the model is terrain: slope and aspect, hydrology, sun and shadow, contours, profiles and cut/fill all run on it, and it can serve as the existing-ground reference until your own survey replaces it.
How to download a DEM or basemap for your site
- 1
Start a project and set the coordinate system
Open or start a project. The downloaded data is placed in the project coordinate system.
- 2
Draw and select the site
In an empty project, draw the boundary of the site and select it, so only that extent is downloaded.
- 3
Open View ▸ Basemap
Choose whether you want the topographic map or the elevation model.
- 4
Pick the source
For the elevation model choose Copernicus GLO-30, GLO-90 or AWS Terrarium; for OpenTopography enter your own key and choose ALOS, NASADEM or SRTM. For the map use OpenTopoMap or your own XYZ service.
- 5
Download and add
STREAM downloads the extent, places it in the project system and adds it. The elevation model comes in as terrain; the map as a basemap layer. If you are offline, it tells you.
- 6
Analyse, then replace with a survey
Run slope, hydrology, sun and shadow or volumes on the downloaded terrain. When your own survey arrives, open it as a new scenario and compare.
| Source | What you get | Key needed |
|---|---|---|
| Copernicus GLO-30 | Global elevation model, downloaded for your area as terrain | No |
| Copernicus GLO-90 | Coarser global elevation model, for large areas | No |
| AWS Terrarium | Global elevation tiles, downloaded for your area as terrain | No |
| OpenTopography (ALOS, NASADEM, SRTM) | Elevation datasets served by OpenTopography | Yes — your own free OpenTopography key |
| OpenTopoMap | Topographic map tiles as a basemap | No |
| Your own XYZ service | Map tiles from a service whose terms you hold | As the service requires |
Supported formats
Frequently asked questions
Can STREAM download elevation data for my site?
Yes. View ▸ Basemap downloads an elevation model for the area you select — Copernicus GLO-30 or GLO-90, AWS Terrarium, or OpenTopography with your own key — places it in the project coordinate system and adds it as terrain.
Do I need an account or a key?
Only for OpenTopography, which needs your own key — a free one, from an account at opentopography.org. Copernicus GLO-30 and GLO-90, AWS Terrarium and OpenTopoMap need none.
What if my area is too large?
STREAM counts the 1°×1° elevation tiles the area needs and, when there are too many, asks for a smaller extent or suggests Copernicus GLO-90, the coarser model meant for large areas.
How accurate is a downloaded DEM?
It is a global model on a coarse grid, so it includes buildings and vegetation and its vertical accuracy is metres, not centimetres. Use it for site selection, context and early studies; for a quantity that will be paid for, survey the site and open that survey in STREAM.
Can I download just my site and not a whole tile?
Yes. If an area is selected on the map, only its extent is downloaded. In an empty project, draw the site and select it first.
Does it work offline?
Downloading needs a connection, and STREAM tells you clearly when there is none. Downloads stay in a cache and in your project, and everything else in STREAM runs offline.
Where does the data come from, and is it credited?
From the source you choose, on demand; STREAM does not bundle it. The source attribution is printed on the map sheet and in reports, and the sources' own terms apply.
Why is there no OpenStreetMap or satellite basemap?
Because of licensing, the built-in basemap is OpenTopoMap only. If you hold a tile service whose terms allow it, add it as your own XYZ source.
Can I free the space the downloads use?
Yes. Downloads stay in a cache, and the Clear Cache button in the Basemap window frees the space.
Try DEM Download in STREAM
Free beta for Windows x64. Works fully offline with GeoTIFF, LAS/LAZ and DXF.
Download STREAM free