LiDARbathymetriat

LiDAR bathymetry, sometimes referred to as bathymetric lidar, is a remote sensing technique that uses airborne light detection and ranging (LiDAR) to map underwater and nearshore topography in shallow, clear waters. It complements conventional land-based LiDAR by extending topographic surveys into the aquatic environment.

The method relies on a green laser, typically around 532 nanometers, which can penetrate clear water to reach the seabed or riverbed. The sensor records two types of returns: the water surface and the submerged terrain. Depth is derived from the travel time of the laser pulse and corrected for refraction at the air–water interface. Modern systems often use multiple returns and may combine green and infrared channels to separate water-column, surface, and bottom signals. Data processing includes georeferencing, tide and water-level corrections, wave motion removal, and calibration with ground truth from conventional bathymetric surveys or sonar.

Platforms for LiDAR bathymetry are primarily aircraft, with some deployment from unmanned aerial systems for shallow, bounded areas. Outputs are point clouds and gridded bathymetric surfaces that can be integrated with onshore LiDAR and terrestrial surveys to create seamless digital elevation models. Applications span coastal zone management, shoreline change detection, harbor and port planning, dredging support, wetland mapping, and riverine habitat assessment. Limitations include penetration depth being restricted by water clarity and turbidity, accuracy depending on depth and conditions, and a need for complementary depth data in deeper waters.