The Research Of Laser Detection Performance Under Dust Environment

Laser has advantages of strong electromagnetic interference resistance, high angle and high range resolution and good monochromaticity. Therefore, laser plays a more and more important role in the modern national economy and national defense construction. Laser beam can interact with the dust particles when transmissed in the dust, it will occur particle absorption and scattering effect, so the laser power decreases at the receiving end and result in system performance degradation, and it may cause failure. Therefore, research on the pulse laser transmission characteristics in the dust is an important foundation of analyzing the laser transmission effect and determining the laser ranging system performance.This paper bases on the background of impulse type short-range laser ranging system. First of all, the paper analyzed ranging system of photoelectric detection characteristic from two aspects of transmitting and receiving system, studied the output characteristic in high frequency environment by the way of series small resistance in sending terminal; the paper found, from the echo signal correlation analysis in receiving end, target and different range will not lead to a change of echo signal shape before the echo signal is saturated. According to this finding, the paper presented a distance measurement method based on cross-correlation algorithm, which is using the relevance ratio of echo signal to demarcate distance. For detection characteristic of sand and dust environment, a pulse laser transmission model, based on Mie scattering theory and Monte Carlo method, was established in quantitative dust concentration and implemented model simulation software. Through building a density controlled airtight chamber and simulation environment test, the paper analyzed the characteristics of ranging system detection in dust environment.The experiment result shows that with the increase of concentration of dust particle, the laser signal present nonlinear lower transmittance. In the different concentrations environment, the rule of model attenuation represents the actual attenuation, and this put forward theoretical basis in the specific work of the laser ranging system’s anti-interference.