Detection of linear frequency modulation laser in high concentration smoke environments

Abstract

In a smoke environment, smoke-suspended particles scatter and absorb laser photons. Smoke not only attenuates the target echo signal but also forms backward scattering. It interferes with the extraction and recognition of the target signal and brings great difficulties to the laser fuze detection. This article establishes a simulation model of the echo of a linear frequency modulation (LFM) pulse laser fuze in a smoke environment based on an improved Monte Carlo and multi-layer perceptron method. While ensuring the simulation accuracy, the echo simulation speed is greatly improved. Meanwhile, the precise ranging of the LFM pulse laser fuze was achieved using the pulse compression Butterworth filter signal extraction algorithm. In low concentration smoke interference environments, the backward scattering interference signal of smoke can be completely removed. The target signal is completely attenuated in interference environments with smoke concentrations greater than 1.4 mg∕m 3 . Smoke interference is present but has a small amplitude and can be excluded by an appropriate threshold. The LFM pulsed laser regime outperforms the pulsed regime in high concentrations of smoke. The research results provide important support for the application of an LFM laser instead of a pulse laser in the field of fuze.