Simulation Analysis of Time Discrimination Module Error in Underwater Short Range Laser Ranging System

Accurate extraction of timing signals in complex laser echoes is a prerequisite for ensuring the accuracy of laser ranging. This paper studied the effect of pulse broadening on underwater laser echo pulse. The time domain expression of echo signal was deduced. Based on Simulink, the distance accuracy simulation model of constant fraction discriminator (CFD) and peak position discriminator (PPD) time discrimination methods was established. The system error of CFD and PPD was simulated. Simulation results show that the system ranging accuracy decreases as target distance and pulse width increases. The range performance of CFD which has certain anti-signal saturation capability is higher than PPD. The simulation results presented here may provide reference for the design of underwater laser ranging system and the compensation of ranging error.