Exploring the Invisible: Remapping Tarragona’s Cova Urbana with Drones and LiDAR Technology
In the heart of Tarragona, beneath the asphalt that thousands of people tread daily, lies a parallel world of rock, water, and absolute darkness. The Cova Urbana de Tarragona is not merely a geological curiosity; it is a labyrinth carved by time that is now, thanks to the alliance between the SIET (Societat d’Investigacions Espeleològiques de Tarragona) and GOAT Drones Solutions, revealing its best-kept secrets through the use of LiDAR technology and a cutting-edge underwater drone.
This collaboration aims not only to update existing maps but to push the boundaries of what technology can achieve in confined and hostile environments.
A Historical Landmark Beneath the Tarraco Roman City’s Foundations
The history of the Cova Urbana sounds like something out of a contemporary adventure novel. Accidentally discovered in 1996 during the foundation works of a residential building, its access is unusual, to say the least: entry is through the -5 floor of a parking garage in the very center of the city. After crossing a door, the explorer will find a dwell and beneath it, a roman aqueduct.
Since its discovery, the SIET has led exploration efforts, cataloging over 1,600 meters of galleries. However, traditional speleology faces insurmountable challenges when galleries narrow or become completely submerged beneath the water table. This is where digitalization and robotics step in to complete the puzzle that human explorers cannot finish due to safety concerns or physical limitations.
SIET’s Challenge: Remapping with Millimeter Precision
SIET’s current project is ambitious: a comprehensive remapping of the cavity. Older maps, while valuable, lack the volumetric precision required by today’s scientific standards. To achieve this, GOAT Drones Solutions has spearheaded the technological consultancy, integrating massive data capture systems.
LiDAR Technology: Light That Sees in the Dark
In the dry galleries, the use of terrestrial scanners and LiDAR (Light Detection and Ranging) technology allows for the generation of point clouds with centimeter-level accuracy. This technology emits light pulses that bounce off the cave walls, creating an exact digital 3D model of the cavity. This “digital twin” allows geologists to study the structure without needing to be physically present, analyzing formations and potential structural risks beneath the city.
Diving into the Unknown: The Role of the Underwater Drone
The true challenge of the Cova Urbana lies in its flooded sectors. Submerged galleries are high-risk environments for cave divers due to water turbidity and the narrowness of the passages. To minimize risks and maximize data collection, GOAT Drones, in a strategic partnership with Drones4Geology, decided to deploy a compact underwater drone or ROV (Remotely Operated Vehicle).
Why Use an Underwater Drone in a Cave?
The advantage of a compact underwater drone over human diving is threefold:
- Safety: We eliminate human risk in narrow, unexplored passages.
- Maneuverability: In spaces where a diver can barely move, a compact drone can rotate on its own axis.
- Documentation: The ability to stream high-definition video to the surface allows the entire team of experts to make decisions in real-time.
Qysea Fifish V6: The Technological Ally Underwater
For this mission, the selected equipment was the Qysea Fifish V6. This underwater drone stands out for its omnidirectional design, allowing it to move in six degrees of freedom. In an environment like the Cova Urbana, where currents can be unpredictable and space is tight, this mobility is critical.
Equipped with powerful 4,000-lumen LED lights and a 4K camera, the Fifish V6 allowed the GOAT Drones and Drones4Geology team to explore siphons and flooded galleries with unprecedented clarity. The goal was clear: to determine whether each gallery ended in a cul-de-sac (dead end) or, conversely, opened into new chambers that until now we could only imagine.
“The use of an underwater drone allows us to see where no one has seen before, enabling a systematic and safe exploration of Tarragona’s underground water resources.”
Technological Synergy: GOAT Drones and Drones4Geology
The execution of this project would not have been possible without expert collaboration. While GOAT Drones Solutions provides expertise in system integration and complex tech project management, Drones4Geology brings specific knowledge in the application of drones for geological and geomorphological studies.
This synergy allows for the transformation of images captured by the underwater drone and LiDAR data into actionable information for SIET. It is not just about “flying” or “navigating,” but about processing that data to understand the geological evolution of Tarragona and ensure the conservation of this hidden natural heritage.
What Have We Discovered?
The first results of this exploration phase have been revealing. The underwater drone has successfully accessed areas where visibility for a diver would have been zero due to sedimentation. Thanks to its stabilization capabilities, the ROV was able to film the walls of the submerged galleries, identifying potential connections with other water filtration systems in the area.
Meanwhile, the LiDAR remapping is offering a volumetric view of the cave that will allow, for the first time, the overlay of the city map with the exact plan of the cavity—something vital for urban planning and environmental protection. As a result of these efforts, SIET presents the following letter of recognition:
The Future of Subaquatic Exploration
The Cova Urbana project is just the tip of the iceberg of what drone technology can contribute to science and industry. At GOAT Drones Solutions, we continue to bet on innovation, using every underwater drone and LiDAR sensor not just as work tools, but as extensions of our human curiosity.
The exploration of the Cova Urbana continues, and every meter advanced by our drones brings us closer to understanding the fascinating world that beats beneath our feet.
Do you need a technical inspection or mapping in hard-to-reach environments? At GOAT Drones Solutions, we are experts in custom solutions using aerial and underwater drones.