基于DLOS算法的激光探测成像仿真研究

发布时间：2018-01-12 21:14

本文关键词：基于DLOS算法的激光探测成像仿真研究　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：激光主动探测技术因其特有的性质,被广泛的应用于国土资源普查、森林火险预警、海面搜救等多个领域。随着相关技术的发展及实际需求的日益增加,如何在恶劣天气条件下实现主动探测成像,同时尽可能地使成像质量得到提升,已成为相关技术领域中亟待解决的问题。目前激光探测成像任务存在投入高,周期长,风险大等制约因素,采用数值仿真分析成为完成探测系统测试和优化设计一种必要的手段。激光主动探测成像仿真采用模块化思路,根据具体探测体制,建立包括激光雷达、大气传输、探测目标模块的系统仿真模型。国外已经针对激光探测成像系统开发了很多功能强大的仿真软件,但可查阅资料中只介绍了仿真软件的功能和图像仿真的结果,对其核心算法、数学模型及仿真依据没有给出详细的说明解释。而我国对激光探测成像仿真方面的研究,主要以分析激光探测系统性能,给出数值结果和关系式为主,能够给出仿真图像的很少。此外,国内开发的成像仿真模型主要以二维目标探测仿真为主,对于三维目标探测这一核心技术的研究甚少,该技术成为国内成像仿真软件开发需重点解决的问题。综上所述,本文将结合激光主动探测成像过程及特点,对传统辐射传输计算方法—视在光线法(LOS)进行改进,开发出一种适用于激光探测成像仿真的辐射传输计算方法—双程视在光线法(DLOS),建立激光主动探测全链路仿真模型;针对二维简单目标和三维复杂目标探测进行仿真计算,并将计算结果与蒙特卡洛法(MCM)计算结果进行对比,验证双程视在光线(DLOS)法的适用性和正确性;研究大气介质光学厚度、脉冲激光发散角、脉冲宽度、探测器成像阵列、探测器接收直径等相关参数对二维目标探测成像结果的影响;讨论不同大气介质场景下的三维目标探测成像结果,对相应大气场景条件的激光探测进行波段优选;结合实际大气介质分布特点,建立非均匀介质探测成像仿真模型,研究分析非均匀介质对成像结果的影响;同时将层析探测结果与非层析探测结果对比,分析层析探测的目标识别优势;扩展研究任意探测方位下的成像仿真模型,为激光探测系统的开发和优化设计提供参考和依据。
[Abstract]:Laser active detection technology has been widely used in many fields, such as land and resources survey, forest fire danger warning, sea surface search and rescue, etc. With the development of related technology and the increasing of actual demand, laser active detection technology has been widely used in many fields. How to realize active detection imaging under severe weather conditions and improve the imaging quality as much as possible has become an urgent problem in related technical fields. At present, laser detection and imaging task has a high investment. Because of the long period and high risk, numerical simulation is a necessary method to complete the testing and optimization design of the detection system, and the modular approach is adopted in the simulation of laser active detection imaging. According to the specific detection system, the system simulation model including laser radar, atmospheric transmission, detection target module has been established. Many powerful simulation software have been developed for laser detection imaging system abroad. However, only the function of the simulation software and the result of image simulation are introduced in the available data, and the core algorithm of the simulation software is given. The mathematical model and simulation basis are not explained in detail. However, the research on laser detection imaging simulation in China mainly focuses on the analysis of the performance of laser detection system, and gives the numerical results and relations. In addition, the imaging simulation model developed in China mainly focuses on two-dimensional target detection simulation, and the research on the core technology of three-dimensional target detection is very little. This technology has become a key problem to be solved in the development of domestic imaging simulation software. To sum up, this paper will combine the imaging process and characteristics of laser active detection. In this paper, the traditional radiative transmission calculation method-apparent light method (LOS) is improved, and a radiative transmission calculation method suitable for simulation of laser detection imaging is developed, which is called double-pass apparent light method (DLOS). The simulation model of laser active detection whole link is established. The two dimensional simple target and three dimensional complex target detection are simulated and calculated, and the results are compared with those of Monte Carlo method (MCM). To verify the applicability and correctness of the double-pass view in the light DLOS method; The effects of optical thickness of atmospheric media, laser divergence angle, pulse width, detector imaging array and detector receiving diameter on the imaging results of two-dimensional target detection are studied. The imaging results of 3D target detection in different atmospheric media scenarios are discussed, and the band selection for laser detection of the corresponding atmospheric scene conditions is carried out. According to the characteristics of atmospheric media distribution, the imaging simulation model of non-uniform medium detection is established, and the influence of non-uniform medium on imaging results is studied and analyzed. At the same time, comparing the results of chromatographic detection with the results of non-chromatographic detection, the advantages of target recognition in tomography detection are analyzed. The imaging simulation model under arbitrary detection azimuth is studied in order to provide reference and basis for the development and optimization design of laser detection system.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN249

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