Research on Pulsed Laser Echo Characteristics in Rainy Environment

Pulsed laser signal data acquisition is difficult in rainy weather, which leads to signal attenuation and degrades target recognition in bad weather. When laser pulses propagate through complex atmospheric conditions, interactions such as absorption and scattering with raindrops attenuate and delay the pulses, shortening the effective transmission range and severely limiting the performance of laser detection in rain. This paper studies the influence of raindrops on the transmission of pulsed lasers based on the theory of geometric optics approximation, and establishes a photon theory simulation transmission model by using the Monte Carlo method. It also simulates the influence of typical parameters in rainfall on the echo characteristics of pulsed lasers. The simulation results show that when the pulse width varies from 10 ns to 20 ns, the echo signal intensity changes significantly, while the amplification decreases when the pulse width changes subsequently. With the continuous increase of the transceiver distance, the intensity amplitude of the echo signal decreases accordingly, which is most obvious within the range of 10 mm to 30 mm. As the rainfall increases, the intensity of the echo signal also continuously decreases, but its impact on the waveform is relatively small. The model and simulation results established in this paper provide a theoretical basis for the anti-interference research of pulsed lasers in rainy environments.