Research On The Spatial-temporal Characteristic Of Pulsed Laser Propagation Process In The Transmittance-reflection Medium

Active laser imaging system has played an important role in detecting the militarytarget, forecasting weather and other aspects. The result of the detection would beaffected when the pulsed laser transmit through the optical medium withtransmittance-reflection and translucence. Properly analyzing the different factors whichcould affect the pulsed laser propagation in the atmosphere is very significant to thesimulation.The core method to simulate the propagation of pulsed laser in the wind and aerosolis Monte Carlo method. The research has achieved the3D target imaging, according tothe energy which received from the target. The main context of this work including:(1) Establish the transmission model of pulsed laser based on the Monte Carlomethod.The research has established the probability models for laser emitting, absorbing,scattering and transmitting process respectively for the purpose of simulating thepropagation process in the medium of transmittance-reflection. According to thetheoretical formula, the accurate of the probability models were verified.(2)Study on the algorithm of active target imaging.Utilize the light splitting and energy compensation to achieve the active imaging forcomplex3D target in case that the probability of which the light could be received isvery small. Seven atmosphere scenes were made up by combining different kinds ofwind and aerosol. Comparing the imaging results in these seven atmosphere scenes, theinfluence of the optical parameters of the medium has been analyzed. In addition, theinfluence of the single scattering on the imaging results was also analyzed.(3) Research on spatial-temporal properties of pulsed laser propagation in theatmosphere.Dividing the laser which received from the detector into several temporal groupsand spatial groups according to distance what the laser has traveled and the positionwhere scattering took place. Establish the model for calculating the spatial-temporalproperties of pulsed laser which was backward scattered form the wind and target.Analyze the influence of different types of wind on the spatial-temporal properties ofthe pulsed laser and the spatial-temporal properties of the multi-scattering light.