GEO Innoter offers a wide range of digital terrain data and cooperates with many suppliers of Remote Sensing materials to provide consumers with digital terrain models of various types with the required accuracy for any territory of the Earth.

Three main types of elevation models are used for various purposes:

  • DEM-Digital Elevation Models,

  • DTM-Digital Terrain models,

  • DSM-Digital Surface Models.

Digital Elevation Models (DEM) – this is a three-dimensional representation of the terrain, represented as an array of points with a certain absolute height, linked to a common vertical datum, which filters out and excludes all ground objects, both built (power lines, buildings, and towers) and natural (trees and other types of vegetation).

First of all, Digital Elevation Models are used in digital cartography and geographic information systems and are the most common basis for representing terrain.

The digital terrain model itself consists of a matrix of numbers, but DEM data can be presented in visual form and used on topographic maps as horizontals, or displayed as colors (for example, using green for the lowest altitudes, shading to red, for the highest altitudes).

The most common ways to digitally represent terrain are as follows:

  • a regular matrix (regular or matrix model) of the earth's surface heights (representation on a regular grid of squares, rectangles, or triangles when its nodes are set to the height values).

  • an irregular, so-called TIN-model (TIN − Triangulated Irregular Network), which includes a set of points with elevation marks, which are triangulated considering the lines of the discontinuity.

  • vector lines (horizontal lines or other isolines with equal or unequal pitch).

The elevation model in the form of a height matrix can be provided in the following formats: GeoTIFF, Arc / Info ASCII Grid(ASC), Band interlieved (BIL), XYZ, or as tiles in the Sputnik KMZ format.

DEM as a TIN model can be provided in the following formats: Wavefront OBJ, 3DS, VRML, COLLADA, Stanford PLY, STL models, Autodesk FBX, Autodesk DXF, Google Earth KMZ, U3D Universal 3D, Adobe PDF.

Horizontal lines (isohypses) are provided in the following formats: Autodesk DXF, Shapefile SHP, Google KML. an irregular grid.

Digital Terrain Models (DTM)

In some countries, DTM is synonymous with DEM and is a three-dimensional representation of the heights of the earth's surface without natural or man-made objects located on it. In the US and other countries, DTM has a slightly different meaning. The DTM includes not only heights and elevations, but also other geographical elements and natural features, such as rivers, ridge lines, etc.

The difference DEM vs DTM is that DTM is a DEM that has been augmented with elements such as break lines and elements other than the original data to correct artifacts created using only the original data. With the increasing use of computers in engineering and the development of fast three-dimensional computer graphics, DTM is becoming a powerful tool for many applications in Earth science and engineering.

The DTM is not continuous and it is not a surface model. From its regularly spaced contour lines, you can interpolate DTM to DEM. The DTM presents distinctive terrain features much better because of its 3D inflection lines and regularly spaced 3D points.

The sources of initial information about the terrain are a variety of data obtained by space optical-electronic surveys and radar equipment, as well as digital optical-electronic aerial surveys, laser and lidar equipment. DTMs are usually created using photogrammetric processing of aerial and space stereo images.

Digital Surface Models (DSM)

The difference DEM vs DSM id that a digital surface model is a three-dimensional representation of the heights of the Earth's surface, including natural or man-made objects located on it. A DSM is a terrain model that includes a terrain model, building outlines, vegetation items, industrial items, and any other items. It is usually considered as a model of a canopy over the surface of the "bare earth".

The DSM can be obtained automatically from stereoscopic satellite images, as well as from stereoscopic digital aerial photographs with different resolutions. To generate DSM and extract features from high-resolution satellite images, an image matching approach has been developed that is in principle applicable to any type of image with linear arrays.

Lidar imaging can also be used to obtain the DSM, which creates a massive point cloud with elevation values. This height can come from the tops of buildings, treetops, power lines, and other objects. The DSM captures natural and artificial objects on the Earth's surface.

The specialized software products available at GEO Innoter allow you to obtain digital terrain models in an automated mode, with the accuracy, form and format required by the Customer.

While DEM is primarily used in cartography and geographic information systems and is the most common basis for digital terrain maps, (DTM) is often required for flood planning, drainage modeling, land use research, geological and other applications, and in planetary science, DSM is useful in 3D modeling for telecommunications, urban planning, aviation, landscape modeling, urban modeling, and visualization applications.

 

Using digital terrain models:

  • For the purpose of creating topographic maps and plans;

  • In geographic information systems;

  • n landscape design, when you need to learn about all the features of the soil and terrain - where water will accumulate, in which place it is better to plant plants.

  • In urban planning, in the design of buildings and structures.

  • In the construction of highways, highways and interchanges.

  • Environmental objectives.

  • Building a digital model of the bottom relief of water bodies;

  • Scientific research: biologists, ecologists, geographers, geologists, and many other scientists choose DEM as their research.

  • Household use of digital modeling in GIS – electronic maps, navigators.

  • Military, aviation and navigation.

  • Visualization of cities for various purposes (tourism, virtual tours, etc.),

  • In navigation systems,

  • In intelligent transport systems,

  • In the simulation of urban risks;

  • In architectural visualization;

  • In telecommunications-positioning of mobile phone transmitters;

  • In the mapping of flood risk.

To calculate the cost of creating DTMs, DSMs and DEMs, orthophotoplanes and other products for the territory you need, send the technical specification to the email: innoter@innoter.com. For further information, please call: +7 495 245-0424.