FGI utilizes Fraunhofer's LiDAR technology for maritime surveying

The highly respected Finnish Institute of Geospatial Studies will utilize the advanced LiDAR system developed by the Fraunhofer Institute of Physical Measurement Technology for future ocean surface surveys. Significant progress is expected in data quality and on-site measurement efficiency, and the state-owned research department is collaborating with Fraunhofer IPM on a joint project. They are jointly committed to creating a compact sensor platform for laser based detection of critical underwater infrastructure such as offshore wind turbines.

Lidar systems excel in long-distance measurement and provide accurate 3D data. Although laser based systems are common for geodetic measurements on land, underwater surveying and topographic measurements traditionally rely on cameras and sonar due to underwater light attenuation and turbidity. However, the two lidar systems launched by Fraunhofer IPM are capable of conducting underwater 3D measurements and aerial depth measurements, marking a significant advancement in this field.

The underwater LiDAR system ULi uses the pulse flight time method to map underwater infrastructure with millimeter level accuracy. The system performs static scanning or scanning while underwater vehicles or ships are in motion. ULi is packaged in a pressure resistant casing, capable of diving into depths of hundreds of meters and measuring objects at distances of tens of meters. The measurement accuracy of this system is ten times that of some sonar systems, and it generates an accurate 3D model of the object.

Through the airborne depth measurement laser scanner ABS, Fraunhofer IPM has launched the first laser system capable of measuring coastal terrain from the air. The system weighs about three kilograms and is the size of a shoe box, with two lasers of different wavelengths. Although traditional laser depth measurement systems are too large and heavy for standard drones, ABS is very lightweight and does not require a flight permit. The system can measure with an accuracy of twice the depth of Secchi, with an accuracy of only a few millimeters.

ULi and ABS systems both use full waveform analysis to check measurement data. This type of signal processing can separate echo sequences modulated by water surface, water surface, and suspended particles, and extract high-resolution terrain data.

In the future, FGI will combine two systems. "The combination of these two systems provides us with a novel and powerful tool for drawing coastlines and 3D measurement objects in deep places," said Professor Juha Hyypp ä, Director of Remote Sensing and Photogrammetry at FGI, excitedly. We will see unprecedented levels of data quality.

The CoLiBri research project funded by the Fraunhofer Association is a collaborative project between FGI, Fraunhofer IPM, and the Freiburg Center for Sustainable Development. The project aims to develop a comprehensive monitoring process for underwater infrastructure and coastal areas, promote collaborative use of the system, and evaluate the potential of its various applications.

Source: Laser Net