Underwater four-quadrant dual-beam circumferential scanning laser fuze using nonlinear adaptive backscatter filter based on pauseable SAF-LMS algorithm

The phenomenon of a target echo peak overlapping with the backscattered echo peak significantly undermines the detection range and precision of underwater laser fuzes. To overcome this issue, we propose a four-quadrant dual-beam circumferential scanning laser fuze to distinguish various interference signals and provide more real-time data for the backscatter filtering algorithm. This enhances the algorithm loading capability of the fuze. In order to address the problem of insufficient filtering capacity in existing linear backscatter filtering algorithms, we develop a nonlinear backscattering adaptive filter based on the spline adaptive filter least mean square (SAF-LMS) algorithm. We also designed an algorithm pause module to retain the original trend of the target echo peak, improving the time discrimination accuracy and anti-interference capability of the fuze. Finally, experiments are conducted with varying signal-to-noise ratios of the original underwater target echo signals. The experimental results show that the average signal-to-noise ratio before and after filtering can be improved by more than 31 dB, with an increase of up to 76% in extreme detection distance.