Design of a high-speed signal processing system for underwater lidar based on complete waveform sampling

The complex and changing underwater environment, along with the presence of various suspended particles, leads to laser attenuation and backward scattering. As a result, the detection capabilities of underwater LiDAR are significantly limited. To address the challenges associated with the backward scattering problem using traditional time discrimination circuits, this paper proposes a high-speed signal processing system for underwater LiDAR based on complete waveform sampling. The system includes the design of a photodiode preamplifier circuit and a main control board with a sampling frequency of up to 2 GHz. With this design, the underwater LiDAR can achieve a ranging accuracy of 0.075m and implement relevant backscatter filtering algorithms. This paper can serve as a valuable reference for the design of signal processing systems for underwater LiDAR