InforShell Technologies

Canada 3D DEM 90m

Mosaicing of customer selected DEM 90m files into visual DEM database
90m horizontal resolution 1m vertical resolution

About DEM 90m data files

The original Digital Elevation Model dataset is provided by NASA, composed of individual data files (tiles) each covering an area of 1 degree longitude x 1 degree lattitude.

When working with elevations of an area larger than 1 deg x 1 deg, mosaicing together several (N x M) DEM 90m tiles is necessary.

InforShell mosaic service - procedure

1. Create a Visual DEM Database (VisualDEMdb) for customer.
2. Add true colour 1km resolution satellite imagery into VisualDEMdb, to serve as an upper level index to the DEM.
3. If customer orders, apply process to fill large DEM 90m data holes.
4. For each DEM 90m file, generate shaded relief false colour image - a full size 2D visualization of the DEM, as shown in Fig 1.
5. Mosaic N x M tiles of 2D visualization images together and add into VisualDEMdb - this serves as a surface to the numerical elevation data
6. Mosaic N x M tiles of elevation data together and add into VisualDEMdb, underneath the 2D visualization.
7. Import customer data if provided, including labels (e.g. area names) and vector diagrams (e.g. region boundaries, rail ways, roads, power distribution networks).

VisualDEMdb area coverage

InforShell has experience mosaicing over a thousand DEM 90m tiles into a single VisualDEMdb, to cover a large country.

According to customer request, InforShell will mosaic any quantity of tiles to cover a custom area, province or country in the world.

Accessing a custom VisualDEMdb

1. Using the eEarth browser with VisualDEMdb, you can view a continuous false or true color image of the customer area at 90m ground resolution (3 arc-seconds), and have cursor point readout for longitude, latitude, and elevation (at 1m vertical resolution).
2. eEarth browser also generates interactive 3D elevation plots with false or true color surface texture, which effectively illustrate drainage patterns and elevation trends, as shown in Fig 2.
3. eEarth is richly featured to facilitate utilization of the elevation database, please see Fig 3, 4, and try the demo below for details.

System requirements

No installation required for VisualDEMdb and eEarth.

Supported systems: MS Windows 98/NT/2000/Me/XP/Windows7[*].
*Note: In Windows 7, switching off Windows Aero themes is required for proper performance.

Mosaic service - price

Typical mosaic processing cost for each 1 deg x 1 deg DEM tile is $250CAD. For LAN multi-user license, or other conditions that may need a custom quote, please contact us at


Canada 3D DEM 90m demo (5MB zip file).
This demo contains mosaic of 2 tiles, i.e. a 1 deg x 2 deg VisualDEMdb.

To facilitate downloading the demo (which contains an executable in the archive), the extension of eEarth.exe was changed to eEarth.txt. After unzipping the downloaded file, please rename eEarth.txt back to eEarth.exe.

Figure1: Image & DEM data

Figure 2: Shaded relief false color 2D visualiation of DEM 90m elevation data, showing hilly Canadian terrain

Figure 3: False color 3D visualization of DEM 90m elevation data

Figure 4: eEarth enables users to draw tracks / notes

Figure 5: View of user track's profile