SatLab Geosolutions took part in an innovative project to map the underwater terrain of an important waterway near a cargo terminal, leveraging its HydroBoat 1500 USV integrated with the HydroBeam M4 multibeam echosounder.
Underwater surveying is essential for a wide range of applications, from ensuring the safe passage of ships and mapping underwater resources to monitoring coastal changes, assessing underwater ecosystems, and inspecting submerged infrastructure like pipelines and cables.
These surveys are indispensable but often come with challenges such as high costs, lengthy processes, and limitations due to water depth and visibility.
Recent technological advancements are transforming this field. Unmanned surface vehicles (USVs) paired with multibeam echosounders (MBES) are setting new standards in underwater surveying by delivering detailed 3D maps of the seabed.
This combination marks a significant advancement, reshaping the underwater surveying landscape while promoting a more sustainable future for oceanic environments. A notable example of their use is in underwater pipeline surveys.
Over time, sediment buildup on the seabed can reduce water depth. Bathymetric surveys identify areas that require dredging, ensuring the waterway maintains the depth needed for large cargo vessels to navigate safely.
This prevents potential grounding incidents, which could damage vessels and harm the environment. Multibeam technology excels in this context, producing highly detailed and accurate underwater topographic data.
Traditional Survey Challenges
Conventional surveying methods rely on large vessels equipped with complex systems, which often face challenges in maneuvering and navigation. While these methods are effective for deep, open-water areas, they are less suitable for shallow or crowded regions, such as the waterway addressed in this project.
SatLab’s Solution
Given the shallow water depth and the presence of active shipping in the area, a portable multibeam echosounder system mounted on a USV was the optimal solution.
The SatLab HydroBoat 1500 USV, an advanced platform designed specifically for multibeam bathymetric surveys, was employed for this project. Its innovative quad-thruster design, resembling a trimaran hull, provides exceptional stability. Additionally, the system ensures uninterrupted operation even if two thrusters fail, with the remaining thrusters propelling the vehicle.
The HydroBoat 1500 USV, combined with the HydroBeam M4 multibeam echosounder, offered several key benefits:
- Efficient data collection: USVs autonomously cover extensive areas rapidly, while multibeam echosounders provide broader coverage compared to single-beam systems.
- Enhanced safety: USVs can operate in hazardous or inaccessible locations, minimizing risks to personnel.
- Superior data quality: USVs collect data consistently, improving the reliability of the results.
Implementation Scheme
Field Data Collection
- Route planning: Survey lines were arranged in parallel to ensure complete area coverage, with spacing adjusted based on water depth. Perpendicular check lines were used to validate measurement accuracy.
- Tide observation: Real-Time Kinematic (RTK) tide verification ensured precise water depth measurements. Continuous monitoring of the GNSS system detected any anomalies, maintaining measurement accuracy.
- Installation and calibration: The transducer was installed in the HydroBoat 1500’s moon pool and calibrated for roll, pitch, and yaw to correct any positional deviations.
Data Post-Processing
The collected data was processed using SLHydro software, following steps including terrain mapping, water depth data verification, chart editing, and graphic production, resulting in a final chart.
Data Post-processing in SLHydro software
Results
High-Resolution Underwater Terrain Maps
The HydroBoat 1500 USV and HydroBeam M4 multibeam echosounder enabled the generation of detailed underwater maps of the waterway, offering precise insights into the underwater landscape.
High-resolution underwater terrain maps
Compliance with IHO Standards
Analysis of calibration data confirmed that the HydroBeam M4 met the rigorous International Hydrographic Organization (IHO) Class A accuracy standards, ensuring the reliability of the collected information.
Compliant with IHO standards
Benefits
The HydroBoat 1500 USV and HydroBeam M4 system successfully completed the survey of this critical waterway. The HydroBoat 1500’s unique moon pool design, waterproof mounting bracket, and compatibility with various third-party multibeam systems enhance its versatility.
Additional onboard sensor support, including ADCPs and side-scan sonars, broadens its applicability for diverse tasks and measurement needs.
Conclusion
This project highlights the capabilities of USV and MBES technologies in delivering precise data for essential activities such as maintaining waterways, ensuring safe navigation, and managing shipping routes.
The integration of these technologies represents a transformative step forward in underwater surveying, enhancing efficiency, safety, and data quality across various sectors. This advancement contributes to better understanding and sustainable management of underwater environments.
