Large dynamic range receiving technology with energy consumption based on wake lidar

Abstract

The multiple scattering of underwater lidar for wake happens in the near field, which leads ordinary receiving system to be saturated due to lack of dynamic range. The receiving system recovery time is usually up to several nanoseconds, which affects the receiving of the far-field signal. For this problem, the attenuation law of laser back-scattering intensity by water is analyzed and a front-end receiver of underwater lidar with energy consumption is developed. A high-speed reverse transient cancellation current is superimposed on the strong peak of near-field part signal to prevent the receiving system from being saturated, thereby restoring the two signals to integrated returned signal waveform. The technical difficulties are analyzed and the solutions are presented. The influence of generation time of transient cancellation current on intensity is discussed. The results of measurement and analysis prove that the transient cancellation current is 5 ns in pulse width, its adjustable step of 122 nA and the adjustable range is 135360 upA. The system suppresses the near-field strong scattering signal successfully and can meet the requirement for the underwater large dynamic range lidar for wake.