Date: 18 December 2019​

​Location: Loire-Atlantique River, France​

​Background​

To address the growing demand for miniaturized and intelligent surveying solutions for rivers, lakes, and reservoirs, OceanAlpha developed an integrated above-water and underwater survey system based on its compact ​SL40 Unmanned Surface Vessel (USV)​​ platform. This solution combines advanced sensors with the ​SL40 USV​ to enable efficient, synchronized data collection for both submerged and surface environments.

​Equipment​

The ​SL40 USV​ was equipped with a multi-sensor package, including:

• ​Multibeam Sonar (MBES)​​ – R2Sonic LLC 2020 model for high-resolution underwater terrain mapping
• ​3D LiDAR​ – Velodyne VLP-16 for above-water structural scanning
• ​Inertial Navigation System (INS)​​ – SBG Systems Ekinox D for precise positioning
• ​Sound Velocity Sensor (SVS)​​ – Valeport MiniSVS for accurate sonar data calibration

This compact yet powerful sensor suite was seamlessly integrated into the ​USV​ platform, overcoming the challenge of deploying multiple high-precision instruments on a small vessel.

​Solution​

OceanAlpha engineered a highly compatible payload configuration for the ​SL40 USV, ensuring optimal performance of all sensors:

• ​MBES, INS, and SVS​ were integrated into the moonpool for stable underwater data collection
• ​Dual navigation antennas​ were mounted on the bow and stern for enhanced positioning accuracy
• ​3D LiDAR​ was mounted 15cm behind the camera using a 3D-printed stand for unobstructed above-water scanning

The ​USV​ followed a pre-set route from the ground control station, conducting ​simultaneous underwater and above-water surveys​ at a designated location in the Loire-Atlantique River.

​Results​

The ​SL40 USV​ successfully captured:

• ​High-resolution 3D data​ of a bridge structure
• ​Detailed underwater terrain mapping​
• ​Precise bank and shoreline imaging​

The field test demonstrated the ​SL40 USV’s​ exceptional stability as a multi-sensor platform, delivering ​clear underwater maps and accurate 3D above-water imagery​ in a single deployment.

​Key Benefits:​

Compact yet capable​ – Small ​USV​ platform with multi-sensor integration

​Efficient surveying​ – Simultaneous underwater and surface data collection

​Proven performance​ – Delivered high-quality results in real-world conditions