A heliostat is a mirror that reflects the sunlight always on the same spot regardless of the sun's position. Whole fields of such mirrors are used for solar thermal power plants. The sunlight heats a medium that is used to generate electrical energy. Modern heliostats such as the Stellio heliostat shown here have a diameter of about 10m. A profound understanding of the behavior of the mirrors under wind loads is needed in order to optimize performance. As part of a research project at DLR, one of the major German research institutions, in Jülich, Germany, Linearis3D has developed a photogrammetric video system that is capable of detecting dynamic deformations of heliostats in all weather and lighting conditions.


To solve the measuring task, Linearis3D created a dynamic photogrammetric measuring system with the following features.
  • 4 cameras with 5 megapixel resolution
  • Measuring frequencies up to 60 Hz
  • Data volume up to 1.2 GB / s
  • Workstation with 128GB RAM
  • over 1000 retroreflective measurement points
  • IP 67 protected cameras and lighting
  • Dynamic orientation of the cameras
  • Multi-Camera Calibration
  • Comprehensive analysis and filtering functions in the software
  • Expandable with additional cameras


The video photogrammetry system makes precise 3D deformation measurments of a very high number of measuring points possible while requiring relatively little time and cost. As a result the system contributes significantly to the success of the research project.

We would like to thank DLR for the excellent cooperation.