Optical underwater sensing – Challenges in hydrography
For about one century the determination of the water depths has been made by evaluating the running time of ultrasound under water.
In connection with the development / improvement of Lidar on flying carrier platforms, laser scanners have been optimized as well in the last two decades. They can detect the surface and they are also able to get through water to detect the topography of the ground when the sight is correspondingly good.
Initial ship-bound laser scanners or systems on autonomous underwater vehicles are in use – they will become even more important for many applications. It will be interesting, when, in addition to the pure running time, the laser beam return signal can also be evaluated, similar to ultrasound or terrestrial laser scanners where it is already feasible. This way it would be possible to get more information about the soil condition.