Data Sources for Elevation Data (FKB DTM)

Elevation Data (FKB-DTM)

Elevation data refers to the height of existing terrain before new interventions. Terrain models (DTM) can be established through both traditional surveying and laser scanning. The DTM can then be used in planning and design tasks. For example, in road projects, new utility corridors, zoning plans, and flood zone mapping. It is also possible to generate contour lines (normally with intervals of 1 or 5 meters) from the terrain model.

Land Surveying

Data collection for digital terrain models, such as soil and rock, for use in mass tracking and documentation is often performed using total station/GPS. The surveyed data is delivered as points with or without terrain lines.

This type of data is imported as point and line objects in application layers. We can then build a triangular network from the data.

The surveyor must have a good understanding of how the triangular network is built to be able to measure the correct terrain model in the field. This is described in more detail in the section Triangulating data.

Laser Scanning

We have airborne and ground-based laser scanning, and there are many areas of application. Airborne laser scanning is increasingly being used to collect detailed elevation data and digital terrain models (DTM) for design. Ground-based laser scanning is widely used to document tunnels.

Laser scanning generates large amounts of data. In Gemini Terrain, we import this scan data into point cloud objects. By handling the points collectively, we achieve better performance.

In the program, we can process this data through:

• Thinning
• Editing
• Triangulation

We can use the data in various tasks such as:

• Mass calculation
• Terrain profiles/sections
• Geometric control