The use of photogrammetry underwater has the ability to make the water disappear virtually, producing clear visibility even in turbid or low-light conditions. The models visually expose structures or environments that are not possible to see using traditional methods producing permanent records that can be continuously assessed and used for whatever the client needs.
The technology is ideally suited to observing and recording wrecks and has been used to monitor and map the condition and stability of many historic artifacts. In addition, photogrammetry is a tool that can be used to forensically examine modern shipwrecks to determine the reasons for sinking without the need to retrieve the vessel. Accurate and precise models can be generated from imagery obtained systematically by divers or ROVs.
Harbours can be areas that accumulate marine debris, either accidently or through deliberate dumping. Harbour authorities may need to know what is underwater and where it is. Significant accumulations can also pose navigational threats in relatively shallow waters.
We approach debris surveys on two levels: firstly, we use broad-scale sonar assessments to show where the main debris fields are, and then secondly, we can use photogrammetry to provide detailed, georeferenced information on the types and volumes of debris, or diver inspections with or without photo/video.
Discarded tyres and lost mooring line, captured using side-scan sonar.
Comparison of models constructed before and after clean-up operations provides evidence for clients or regulators that the work has been carried out appropriately.