Laser Range Doppler Imaging And ISAL Imaging

With the development of lidar,lidar imaging is of great significance in the imaging technology.It's possible to get high resolution of the image with the short wavelength of lidar.In this paper,the principles of lase range profile,lase range Doppler image and inverse synthetic aperture lidar image in lidar imaging are introduced in detail.The laser range profile and range Doppler image with narrow pulse and wide spectrum are simulated and analyzed.ISAL imaging frequency is improved from GHz to THz with the GPU parallel acceleration of the algorithm,and the ISAL images of objects with different roughness and incident angles are analyzed.The details of the works are as follows:1.To establish the throretical basis for the lidar imaging,the models and methods commonly used in the study of object laser radar scattering characteristics are introduced,including laser radar cross section,bidirectional reflectance distribution function and Kirchhoff approximation method.2.The simulation model of laser range profile is introduced,and the laser range profile in narrow pulse mode and wide spectrum mode is studied respectively.The study of object shape,material and surface roughness on one-dimensional laser range profile are simulated and analyzed with the consideration of occlusion effect.3.Based on the Doppler shift and laser range profile of rotating object,laser range Doppler image is studied.The range Doppler images of the object in two modes of rotation and precession are simulated,and the range Doppler images of different objects and different incident angles are compared and analyzed.4.A laser range profile model containing multiple scattering is presented and calucated with bouncing ray method and bidirectional reflectance distribution function.The accuracy of numerical calculation is verified by dihedral structure.With different targets and materials,the difference between the primary scattering LRP and the LRP containing multiple scattering are compared and analyzed.5.The rough surface and cone is simulated with Monte Carlo theory,and then the scattering field of rough object is calculated by Kirchhoff approximation,at last the ISAL images of rough object in turntable mode is carried out.The efficiency of the algorithm is optimized by GPU parallel method,which decreases the time of computering program.The ISAL images of disk,plate and cone with different roughness are analyzed and compared.