Surveying Underwater Cultural Heritage Sites
Scientists use a variety of technologies to survey underwater cultural heritage sites. One of the more common methods used to locate a wreck is sonar. Sidescan and multibeam sonar technology use sound waves to create images of the seafloor. Irregularities in the map, such as an unexpected “bump” can help scientists narrow down the region where they may find a wreck. Another sonar method, Synthetic Aperture Sonars (SAS) use an artificial array to generate higher resolution imagery than traditional side-scan sonars. This method is less frequently used because of cost and availability.
Once wrecks have been located photogrammetry technologies have become widespread tools to rapidly document and record details in high resolution. After recording a series of overlapping photos or screen captures from video, structure from motion software is used to create a two dimensional map-like image of the wreck and three dimensional model. Laser scanning is an emergent technology for documenting underwater shipwrecks in high resolution. The results are detailed three dimensional representations of the wrecks. Cost and availability are limiting factors in its use.