With USV technology being rolled out across port authorities and governing organisations, it was becoming increasingly important for further research focusing on the capabilities of the platform. The research industry partner, the Port of London Authority, was particularly interested in the platform’s ability to meet engineering standards within port structural surveys. Its potential has not been widely covered within the industry or by further research, with previous academic papers only highlighting its ability for nautical charting (Specht et al., 2020).
The scope of work included a relative accuracy assessment of USV MBES measured against terrestrial LiDAR, with both vertical and horizontal structural uncertainty (95% confidence level) measured at 5.2cm and 2.2cm respectively. Another key objective identified platform-induced errors across the works; with yaw misalignment, platform turns and vertical altitude separation effecting the quality of USV MBES. Across the vessel comparison, the USV outperformed its manned equivalent providing additional structural coverage and hit-count for the engineer. However, the stated platform errors increased dataset uncertainty, reducing footprint conformation to IHO exclusive order (90.73%) and the clarity of structural data. This ultimately would reduce measurement confidence for engineering projects and would significantly affect its deployment over the manned vessel.
The works also noted that issues such as platform turning and vertical separation in GNSS altitude readings could be mitigated with altered platform integration, increasing the suitability of the platform within this scope. A balance must also be drawn between platform stability and vessel draft, which directly links to structural coverage and the discussed yaw errors.
Hydrographic Surveying MSc graduate at University College London, now specialising in Subsea LiDAR Projects for Offshore Construction with 3D at Depth.