Topographic surveys include the creation of digital terrain models (DTM), height models (DHM), and surface models (DSM) with high point density. This data is obtained through LiDAR flights and photogrammetric recordings, then processed with specialised software to generate a dense 3D point cloud. These detailed measurements serve as the basis for various topographic products, and point clouds can be transferred for further processing in standard formats.
Ready-to-use products
- Digital Height Models (DHM): Represents topography through a grid of points, either regular or irregular, in the form of a classified point cloud, with each point representing a height value.
- Digital Terrain Models (DTM): Represents the actual land surface, including only ground points, without buildings, vegetation or other overlying structures.
- Digital Surface Models (DSMs): Include land surface features such as buildings and vegetation, providing a complete representation of elevations.
All models are supplied ready to use for integration into GIS, CAD and planning systems, tailored to project needs.
Formats and representations
- Elevation points/grid: Simple form of DTM, representing elevations with XYZ coordinates, transferred as clouds of classified or filtered points.
- Contour lines: Connects points of the same height, representing the height profile on topographic maps and geospatial data.
- Raster elevation models: represent the terrain as a raster image, with points (pixels) arranged in a matrix and defining the area by colour or grey value.
- Polygonal grid/mesh model: the DTM can have different structures, including triangular, grid or hybrid grids, with breaklines defined to represent notable changes in terrain.
- Terrain Profile: Derived from DTM or point clouds, it shows height along a profile line as a diagram, giving a detailed representation of the terrain.
