Automatic determination of sail shape and sail trim using photogrammetry.
What is Digital Telltales?
The Digital Telltales project, part of the "Proeftuin op de Noordzee" and co-sponsored by the Municipality of The Hague, focuses on pioneering innovations in sailing. The goal is to accurately measure and analyze sail shape and trim changes using advanced photogrammetry. This unique measurement system offers new insights for top athletes and sailmakers alike.
Photogrammetric engineering at sea
Geodelta developed a prototype camera system specifically for this project, consisting of two waterproof cameras at a fixed base distance. This system takes simultaneous images of the sail, which is crucial because of the constant movement of the sailboat and sail. Geodelta's in-house developed software processes these images into accurate 3D point clouds. This allows the sail shape to be captured with a precision of 15 millimeters or better.
Tests performed and results
The project went through several field tests:
- Test in the warehouse: The first tests confirmed that it is possible to capture the sail shape with photogrammetry.
- Test with wind: A fan was used to measure the impact of different trim positions. The data was validated with laser scans from TU Delft.
- Outdoor test: Under natural conditions, it was proven that the system also functions accurately at sea while sailing.
Two different trim modes with both photo and sail shape determined by photogrammetry.
Follow-up and impact
The results of the digital telltales can now be used for further development and professionalization of the sport of sailing. There are also opportunities outside the sport. In the context of sustainable transport, it is becoming increasingly interesting to also provide transport ships with sails. Geodelta's photogrammetric technique, originally developed for aerial photogrammetry, has shown that sails can also be accurately recorded in three dimensions.
