State of the Science Stories: Scientific Diving | Assemble+

State-of-the-Science Stories: Scientific Diving


ASSEMBLE Plus’ Scientific Diving team are currently focused on developing their capabilities in stereophotogrammetry, otherwise known as “structure from motion” or “3D photogrammetry”.

Stereophotogrammetry is a methodology that uses normal imagery (photos, videos, micrographs), to generate three-dimensional point clouds that stitch the images together to build a 3D image.

The beauty of the technique is that it only needs images from a single camera, and there is no need to control set distances or angles. This makes it much easier for the diver holding the camera! Such images can be used to make retrospective, reliable measurements even down to the millimetre scale (if the images are of high enough resolution); it is as if the subject is sitting your own lab!  Because the models are constructed mostly from close-up imagery, the water effectively disappears. In low-visibility environments, large-scale targets become totally visible, and things that could never observed with the human eye can be seen. More importantly, the amount of information that can be gathered in one dive (or voyage using a drone or remotely operated underwater vehicle) is significantly more than studying the object directly underwater. It is, therefore, time and resource efficient.

Stereophotogrammetry has many applications: habitat mapping, measuring the volume of coral, estimating carbonate production rates, calculating erosion or biofouling rates on underwater structures. It could also be used to capture a moment in time for a time-series or historical database; if, for example, subsequent years of volumetric changes of environments such as ice shelves were required. Those benefitting from this technique could be geologists, surveyors, archaeologists and intertidal biologists.


What is ASSEMBLE Plus doing that is different?

Standardising Stereophotogrammetry Methodologies

With computer-based work, it is important to be confident of the accuracy and reliability of the results. The ASSEMBLE Plus researchers are working in multiple teams, operating from the Arctic to the Mediterranean, to interrogate the results that their respective models are generating to test their accuracy and precision. One of our goals is to develop a standard methodology that can be applied by different teams,  such that the same results are always produced no matter which team is using them or which project they are working on. 


What next?

  • It is hoped that the underwater observation network that has been created will further expand, and will demonstrate the value of diver-based, sub-tidal physico-chemical observation (e.g. sea-surface temperature).
  • The next workshop will take place in December 2019 at the Hellenic Centre for Marine Research in Heraklion (Greece).


Potential Impact

The oil and gas industry are using the same stereophotogrammetry software as used by the ASSEMBLE Plus researchers. They will have adapted the software to their own use-cases, which is where their intellectual property lies. They have also developed their own methodologies using unmanned underwater robots. While the focus of ASSEMBLE Plus is on standardising the approach for scientific teams, commercial opportunities will be sought for the outputs of this research, as well as the skills that are developed in the course of doing the work, particularly as the commercial licenses for the software and the advanced levels of computing power required are costly to resource.




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