Full Link Simulation Of LADAR Echo Signal Based On GPU Programming

LADAR(Laser Detection and Ranging)is widely used in military and civilian applications due to its high imaging resolution,stealthiness,portability,and flexibility.LADAR provides reliable and consistently densely sampled information points in an automated and fast manner,and its applications have expanded from battlefield surveillance and reconnaissance to terrain mapping,intelligent driving,3D modeling,and various other aspects.Full link simulation of LADAR echo signal is an integral and important part of the design and manufacturing process of LADAR.Digital simulation of LADAR based on computer graphics and fast rendering can effectively reduce the experimental cost and R&D risk,accelerate the research progress,and save research funds.In this study,the full-link real-time simulation of the LADAR echo signal is done from the principle of direct detection LADAR.First of all,starting from the basic principle of LADAR,according to the LADAR distance equation,modules in the whole process of LADAR from transmitting to receiving are analyzed and modeled,and the characteristics and correlations of various parameters in the simulation process of LADAR are determined,while the basic theory of computer rendering is introduced to lay the foundation for the construction of the simulation platform of LADAR.Secondly,based on the computer rendering theory mentioned in the previous part and the construction patterns of software engineering,the simulation process of the platform is analyzed and modeled,and the concepts of rendering engine and high-performance parallel computing are introduced,with the aim of speeding up the rendering and improving the real-time performance of the simulation.For atmospheric turbulence,this thesis models its intensity,introduces the Rytov variance and scintillation indices of light intensity commonly used in atmospheric turbulence modeling,establishes a numerical simulation of atmospheric turbulence effects based on a typical light intensity scintillation model,implements and analyzes the effects of atmospheric turbulence of different intensities on the radiation intensity distribution of the return waves in the simulation platform,and the influence of atmospheric turbulence on laser transmission is analyzed.Finally,the simulation platform is built to simulate and obtain the echo signals of laser from the target,and the intensity distribution and time distribution of the echo signals,as the results are analyzed respectively.Meanwhile,quantitative input/output and analysis are performed for different cases of atmospheric turbulence,which is a unique interference of LADAR,to obtain the results of LADAR imaging performance under different atmospheric turbulence cases.