#8 Introduction to underwater photogrammetry
Water covers two-thirds of the earth’s surface with an average depth of more than 3500 m and a maximum depth of almost 11000 m (the Mariana Trench), far greater than the highest peak of the world (the mount Everest with nearly 9000 m). With its intrinsic characteristics, water is a naturally unsuitable environment for men, but still, all over the world, an uncountable number of human vestiges exist underwater. Not only archaeological sites, but shipwrecks, ancient and modern, commercial and military, submarines and aircraft. Modern and functioning engineering constructions, such as oil platforms, undersea pipelines, floating wind turbine, etc. are also increasingly populating the ocean. Aquatic ecosystems play a fundamental role in the delicate balance of nature; unraveling their complex and fragile interactions is today more than ever of paramount importance. Consequently, underwater explorations, observations, inspections, and measurements have gained more and more importance and are becoming more common, also pushed by developments in technology, equipment and algorithms.
This tutorial aims at providing the audience with an introduction to the crucial aspects of underwater photogrammetry, as key technique for studying and understanding the underwater world in many application fields, such as exploration and mapping, industry, metrology, archeology, biology, etc.
Specifically, the following topics will be covered:
- Image formation underwater: optical considerations
- Photographic aspects: light absorption, scatter, white balance, color correction
- Flat vs Dome ports (from optical to geometric influences in underwater photogrammetry)
- Camera calibration approaches, with parallelism between photogrammetry and computer vision(no single viewpoint)
- Reference systems and accuracy assessment
- Autonomous navigation and mapping
- Stereo vs monocular systems (laser scaler)
- Overview of applications: needs and approaches in archeology, ecology, metrology and industry.Afternoon:
- Hands-on with provided datasets: white balance, color correction, photogrammetric imageprocessing. Alternatively, participants can decide to work on their own images
- Participants are also encouraged to showcase their applications and discuss issues faced in theirpractices.
Resources that will be distributed: all the teaching material (i.e. the PowerPoint presentations, image datasets).
Target audience: PhD students, researchers and practitioners
Level: beginner to intermediate
Expected number of participants: 15-25