Digital Terrain Mapping / Digital Elevation Model / DTM Model
Digital terrain modeling (DTM), which is also referred to as digital elevation modeling, involves the creation of a digital representation of the terrain and the terrain topography. Although maps with topographic information have been created for centuries, these elevation data have only recently been recorded in such a precise digital form that digital models of the land topography can be created. If necessary, a point-to-point land topography can be used to create a DTM that meets your requirements.
The digital elevation model (DEM) is a representation of the earth relief used for geodata analysis and modeling. Elevation data are recorded in the form of points with a defined interval and cutting lines. Digital elevation models are usually created as an important basis for the planning and construction of infrastructures such as roads and railways.
In connection, open-cast mining and the preparation of landfills, the change in the soil can be documented by repeated measurement of digital elevation models and changes in volume can be calculated.
WHY DTM IS USED
The digital terrain model can be used to model water flow or other movements or for land use studies, transport system planning and geological applications. Other applications include the creation of high relief physical maps, flight simulator programs or other visualization and modeling applications. Digital terrain models are also integrated into geographic information systems.
HOW DIGITAL TERRAIN MAPS ARE CREATED
There are many ways to display the information on a digital terrain map. Often, this data is collected using remote sensing devices rather than direct surveying methods. Radar satellites are widely used to create models of large terrain. Although these satellites often only have a resolution of around ten meters, they can obtain information about an area several tens of miles wide in one pass. There are other methods. A pair of captured images at different angles, taken from an airplane or satellite, can be used to infer the terrain. The first digital terrain models using this method were created in 1986 for a large part of the planet using SPOT 1 satellite data.
In many cases, digital terrain models are generated from contour maps, which are often created using direct land surface topography. Contour line data are obtained using various topography methods, including LIDAR, Doppler radar, theodolite, or total station surveying equipment. With GPS, altitude data can be related to a specific location. This information can be converted into a digital contour map or a terrain model, which converts the raw data into a model with which the viewer can “visualize” the landscape in a virtual way.
While contour maps can connect the same height points but do not provide data for intermediate points, DTMs can provide continuous height information throughout the model. In addition, in contrast to two-dimensional contour maps, a digital terrain map provides 3D images. In many cases, “flight programs” or similar programs allow the user to manipulate the map to see all areas and angles of the terrain.
A digital terrain model generally only includes the surface of the earth without vegetation as well as buildings or other artificial features. This is sometimes referred to as the bare earth model. A digital surface model, on the other hand, shows these properties in addition to the natural terrain. The problem with some of the topography methods used to create these models (e.g., radar) is that they reflect the highest elevation in a particular location, be it on a tree, building, or bare ground that is crooked can be the rest of the model.
Eratost has derived a number of digital and graphic products from a digital elevation model, including:
The results are checked manually with a powerful processing technique. Highlights in artificial structures or vegetation can be removed and gaps can be closed. The last step is to generate DTM.
Contact Eratost technologies topography today for more information on digital terrain modeling and to discuss your needs.