as the MSS is a high resolution MBES. A Marine Laser Scanner is mounted on the vessel, which simultaneously acquires the terrestrial component of the model, negating the use of a separate land or UAV survey. Additionally, a second sonar, a standard MBES is used to im- age the subsea terrain. Dynamic acquisition allows the inspection of environments in a mat- ter of hours, whereas a similar static acquisition campaign would be prohibitive in either time or cost. Similarly, the use of physical diver inspections can be reduced by use of such surveys, their deployment can be informed by the identification of damaged infrastructure from the sonar dataset. Sediment mobility and seabed monitoring can also be readily performed, as successive models can be directly compared to each other. Rapidly advancing sonar technology has resulted in accuracy levels that approach terrestrial LiDAR, and the deployment of MSS on a dynamic platform allows for the dramatic upscaling of high-resolution inspection surveys, when compared to static acquisition. We hope to continue to explore and develop the technology to inspect other sub- merged assets, improving survey efficiency and accuracy for our clients.
Bibby HydroMap bridge data
acquired dynamically at a speed of around 2-5 knots. Georeferencing is governed by Inertial Navigation Systems (INS), so every point has a real-world position at the time of acquisition. GNSS post-processing techniques are then often deployed to correct for environmental or technical factors such as multipath or signal drop out, resulting in accu- racy levels approaching that of traditional static deployment (2-5cm). This acquisition methodology has been transferred to MSS operation,
Bridge Bibby HydroMap
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may 2020
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