Remote Sensing

Using modern remote sensing methods, we create a digital twin of the city and other locations.

Remote Sensing enables the creation of detailed digital twins of reality with applications in various spatial analyses – whether it be aerial photographs, 3D digital twins of cities, thermal imaging, or orthophoto mosaics etc. We obtain data primarily through a combination of collection methods such as surface laser scanning (LiDAR) and aerial photography in visible or invisible parts of the electromagnetic spectrum.

When does photogrammetry help?

  • In the creation of orthophoto mosaics – for mapping, documentation, and interpretation of landscapes, cities, areas etc.
  • In the reconstruction of shapes and dimensions (3D modeling) with applications in heritage conservation, architecture, hydrology, and other fields.
  • In volume calculations – determining volumes in quarries, industrial areas, etc.
  • In the creation of photoplans – for surveying historical building monuments.

 

What is photogrammetry? 
Photogrammetry is one of the measurement methods of remote sensing. This field primarily deals with the processing and interpretation of photographic images, where 2D images of reality can be used for modeling in 3D space.

How is a 3D digital twin created using LiDAR technology?

Light Detection And Ranging (LiDAR) is a method of using lasers to render the scanned object or Earth’s surface. The following steps lead to the creation of a 3D model:

Data collection with a LiDAR sensor and creation of a point cloud

LiDAR technology sends laser beams to the objects of interest, which then reflect back to the recording device. The data obtained in this way is processed into a point cloud, which contains a large number of 3D points representing the shape, dimensions, and position of the objects of interest on the Earth’s surface. Based on simultaneously taken aerial photographs, the resulting point cloud is colored with real colors.

Classification of point clouds and creation of digital models

By sorting the point clouds, we obtain specific groups of interest points from which we create digital models – a Digital Terrain Model, which includes only the Earth’s surface without vegetation, buildings, and other anthropogenic features, or models with height information about vegetation and other natural or artificial objects, i.e., a Digital Surface Model. One of the visualization methods can also be texturing the models using aerial photographs.

What is the use of a 3D city model?

3D city models are useful tools not only for professionals but also for ordinary citizens. They offer descriptive information about buildings and other objects and are compatible with CAD/GIS data formats. They are useful in presenting urban or development projects. Ordinary citizens can better familiarize themselves with the future development of their settlement thanks to the 3D city model. Digital models are also important in studies applying spatial analyses such as noise propagation, natural hazard analysis and other environmental aspects. 3D models are becoming an essential tool for cities striving for modern development.