Study On Laser Beams' Transmitting Characteristic Of Non-Scanned Imaging Lidar

Lidar with high resolution and intense anti-interference can be used to range, track angle, measure the velocity of target, indicate the mobile target, and also can be used to follow hedgehop target. Just it is provided with nice hidden performance, it has been extensively used in military technology equipment. Thereinto, non-scanned imaging lidar does not use the machanical sanned system, so the performance of imaging frame has been greatly improved which is the development derection of lidar. The main work of this thesis is to disscuss the principle of non-sanned imaging lidar, built the laser beam propagation model and study the propagation properties of laser beam.The system of non-sanned imaging lidar determines that its imaging quality is related to the energy distribution of laser beam.This thesis firstly introduces the basic theory of partially coherent beams mutual intensity propagation, propagation of laser beam in atmosphere and target characteristic of lidar. Using the theory of partially coherent beams mutual intensity propagation,the principle of Huygense-Fresnel and the theory of wave propagation in atmosphere, the propagation model of laser beam through the atmosphere is built.By studing on target characteristic of lidar, using calculating formula of lidar cross section of basic target, the spacial distribution formula of laser intensity after being scattered by target to the detector was deduced.Calculation results shows that the laser intensity distribution from target becomes non-uniform.According to the research result of laser intensity changing in laser propagation process of non-scanned imaging lidar, the propagation model of non-scanned imaging lidar is built. The whole simulation process is designed by the language of matlab. And the simulation result indicates atmospheric attenuation, atmosphere turbulence and the target scattered characteristics seriously influence the intensity distribution, the center of intensity distribution fluctuates strenuously,the edging of the power becomes rather weak and there is a large discrepancy between the center and the edging of the power distribution in the laser propagation process, which induces the reduction of the imaging quality...