For years, mapping the seabed and lake beds was slow, expensive vessel-based work. Airborne bathymetric LiDAR changes this: instead of covering the area by boat, an aircraft scans it from above — quickly, continuously and over wide areas.
How does it work?
The system emits laser pulses. Part of the energy returns from the water surface and part penetrates the water column and returns from the bed. The difference between the two returns, with refraction corrections, gives the water depth at every point.
Why a combined system?
The Leica Chiroptera 4x includes a topographic and a bathymetric laser. Together they scan land, shoreline and seabed in a single flight, producing one continuous model without a gap between sea and land.
Limitations worth knowing
Penetration depth depends on water clarity: turbid water reduces it. Flights are therefore planned for suitable weather and clarity, and deeper areas are sometimes completed with acoustic methods.
Applications
Port and marina design, coastal management and erosion monitoring, lake and reservoir mapping, underwater infrastructure and navigation safety.