German-Indonesian Team Pioneers Advanced Seabed Mapping Off Indonesian Coast

The completion of one of the decade's most advanced oceanographic missions recently took place off the coast of a small Indonesian island. Researchers from Universität HafenCity (HCU) in Hamburg collaborated with the Institut Teknologi Bandung (ITB) to achieve a groundbreaking feat: the first-ever integration of data derived from two distinct lidar systems—one airborne and one submerged. This synergy resulted in the creation of an exceptionally detailed, three-dimensional model of the near-shore marine environment.

This pioneering project, which received crucial backing from the Fraunhofer Institute for Physical Measurements (Fraunhofer IPM), marks a significant evolutionary leap in oceanic cartography. Traditionally reliant on sound (sonar), this new methodology shifts the focus entirely to light, establishing a new benchmark for future mapping endeavors.

Fusing the Aerial and the Submerged

The engineering team deployed two specialized instruments: the Aerial Laser Scanner (ABS) and the Underwater Lidar (ULi). These systems were designed to survey the exact same physical space but from radically different perspectives—the ABS viewing from above the surface, and the ULi operating beneath the waves.

Mounted on an aircraft, the ABS provided a comprehensive panoramic view of the coastal topography. In contrast, the ULi, developed specifically by Fraunhofer IPM, generated a highly precise underwater model. This device boasts a millimeter resolution and is capable of capturing up to 100,000 points per second, offering unparalleled clarity of the seabed structure.

This synchronized operation represents the first successful effort to merge aerial and underwater datasets into a single, cohesive system. It allows scientists to visualize the coastline not as a static boundary, but as a dynamic, living structure where light interacts—reflecting, refracting, and ultimately defining the ocean floor's intricate relief.

The Science of Illumination and Depth

The environmental conditions surrounding Prambuka Island proved to be ideal for the mission, offering visibility up to 12 meters. This clarity was essential, enabling the team to perform the inaugural test of dual light calibration, simultaneously measuring light from both the air and underwater sensors.

To rigorously verify the precision of the new technique at depth, specialized objects were strategically placed on the seabed. These served as calibration beacons for both lidar units. The resulting data confirmed the technology's extraordinary capability: it can effectively supersede even the most advanced sonar systems, accurately pinpointing objects with millimeter precision, even at depths extending into hundreds of meters.

Professor Harald Sternberg, who heads the Hydrography and Geodesy department at HCU, commented on the significance of the achievement:

“For the first time, we have obtained a complete, harmonious 3D picture of the submerged world. Light is transforming into a tool for discovery—acting as a bridge connecting the sea and the sky.”

The Ocean as a Technological Mirror

This technological advancement unlocks vast new potential for monitoring delicate marine ecosystems. Furthermore, it provides superior control and inspection capabilities for critical offshore infrastructure, ranging from large-scale wind farms to complex oil and gas platforms.

The successful fusion of data streams from the ABS and ULi systems powerfully demonstrates how integrating diverse scientific approaches can illuminate previously unseen layers of the ocean, pushing the boundaries of what is observable beneath the surface.

This project serves as a potent reminder that the ocean is more than just a force of nature; it is a mirror reflecting the Earth itself, where every drop of water reflects the technology of light and the persistent human drive to see deeper.