Canting heliostats with computer vision and theoretical imaging Articles uri icon

publication date

  • November 2022

start page

  • 957

end page

  • 969


  • 200

International Standard Serial Number (ISSN)

  • 0960-1481

Electronic International Standard Serial Number (EISSN)

  • 1879-0682


  • Solar Power Tower technology requires accurate techniques to ensure the optical performance of the heliostats both in commissioning and operation phases. This paper presents a technique based on target reflection to detect and correct canting errors in heliostat facets. A camera mounted on the back of a target heliostat sees an object heliostat and the target facets in reflection. The pixels difference between detected and theoretical borders determines the canting errors. Experiments in a lab scale testbed show that canting errors can be corrected up to an average value of around as low as 0.15 mrad. Experiments were also performed on a real heliostat at Plataforma Solar de Almería. As a result, canting errors (up to 5 mrad) have been reduced below 0.75 mrad. Mirror slope errors, which can be noticeable in large facets, becomes the largest source of inaccuracy in the presented method.


  • Industrial Engineering
  • Mechanical Engineering
  • Physics
  • Renewable Energies
  • Robotics and Industrial Informatics


  • solar power tower; heliostat optical quality; pinhole camera model; edge detection