YellowScan Launches Bathymetric LiDAR for Mapping Underwater Terrain from the Air

French company YellowScan has launched Navigator, a drone-mounted bathymetric LiDAR system that measures underwater terrain in rivers, lakes, and coastal areas without the need for boat-based sonar. The system uses a green-wavelength laser that penetrates water ranging from clear to moderately turbid, enabling a single land-and-underwater survey within one shared coordinate system.

Standard topographic LiDAR stops at the waterline. Its beam cannot penetrate water, so anyone wanting to document both what lies above ground and what lies beneath a river or bay has had to run two entirely separate surveys: a drone or aircraft flight for the land portion, and a boat-mounted sonar survey for the underwater portion. Merging these two data sources is inherently tricky, since they come from two different reference systems that must be aligned after the fact, and often involve two separate survey teams and budgets.

A laser that can penetrate water

YellowScan's solution is built around changing the laser's own wavelength. Instead of the infrared beam familiar from land-based LiDAR systems, Navigator emits a beam in the green spectrum, which can pass through a water column and return a signal from the submerged ground beneath it. The result is a single continuous dataset, collected in one drone flight, covering both the adjacent land and the underwater terrain within the same coordinate system.

• Technology type: Green-laser-based bathymetric LiDAR
• Platform: Drone-mounted, no boat or underwater equipment required
• Penetration range: Water from clear to moderately turbid
• Launch date: Early 2024
• Manufacturer: YellowScan, a French LiDAR company

One survey instead of two separate surveys

The system's practical advantage is most relevant in fields where measurements must be accurate on both sides of the waterline at once. Monitoring riverbank erosion, coastal engineering design, and flood-risk modeling are classic examples where mismatches between land data and water data can distort engineering conclusions. Unifying both surveys into a single geographic reference system reduces the risk of alignment errors and shortens fieldwork time, at least on paper.

One practical question remains that every survey team will need to check for itself: how clear is the specific water source being examined, since the green laser's performance depends directly on water turbidity. In murky rivers or muddy water after a storm, results could be considerably weaker than the samples shown in marketing materials.

Expanding an existing product line

YellowScan is no newcomer to the field. The French company already sells airborne LiDAR systems to customers in forestry, infrastructure corridor mapping, and construction surveying, and Navigator marks its entry into a niche that until now was mainly the domain of specialized, expensive bathymetric survey vessels. Moving this niche onto an easier-to-operate drone platform could lower the entry barrier for smaller survey companies that could not previously afford to charter a dedicated survey vessel.

In a market where every LiDAR player, French, American, or Chinese, is trying to carve out its own technological niche, YellowScan's choice to focus on bathymetry looks like an attempt to differentiate itself from larger competitors focused mainly on classic land surveys. Still, the system's price and its accuracy under varied field conditions, beyond the lab conditions shown at launch, remain factors that will only become clear once real customers start using it in the field.