声光脉冲压缩激光雷达系统设计与仿真

发布时间：2018-11-07 16:33

【摘要】：由于激光雷达工作频率高，，载波波长短，因此，在成像分辨率等方面较传统微波雷达具有明显优势，越来越多的应用于对地感测、遥感等民用和军事领域。但是，由于激光发射功率和接收灵敏度限制，造成激光雷达的作用距离与传统微波雷达存在较大差距，提高作用距离成为激光雷达领域研究热点。在诸多提高作用距离的方法中，脉冲压缩技术具有较大的提高潜力，因此，基于声表面波脉冲压缩激光雷达系统的性能分析和仿真研究具有较高的理论价值以及实际应用价值。本文首先分析激光雷达系统时宽-带宽积特性，说明了具有宽时宽-带宽积的信号是可以进行脉冲压缩的，给出了发射线性调频信号的激光雷达脉冲压缩原理和过程。得到了采用脉冲压缩体制的线性调频激光雷达接收机特性，该系统接收机接收的信号具有窄脉宽和高峰值功率优势，同时满足激光雷达远距离和高距离分辨率要求。本文基于脉冲压缩技术原理设计了声光脉冲压缩的线性调频脉冲激光雷达系统，详细分析了声光脉冲压缩的线性调频脉冲激光雷达系统工作过程，得到了目标距离方程和距离方程与噪声相对关系。其次，根据线性调频脉冲压缩激光雷达原理，进行了线性调频脉冲压缩激光雷达的匹配滤波仿真研究，通过数值仿真得到了通过目标距离变化与输出相关峰变化的线性对应关系，证明了基于声光相关器的测距激光雷达系统的可行性。最后，对基于声光脉冲压缩的线性调频脉冲激光雷达信号处理进行研究，完善该系统的设计方案，建立了脉冲压缩激光雷达系统仿真模型。在这一模型基础上，对系统性能指标进行研究，获得了使用脉冲压缩技术可以有效地提高激光雷达系统信噪比，显著提高系统的探测距离等性能的重要结论。
[Abstract]:Because of its high operating frequency and carrier wave length, lidar has obvious advantages over traditional microwave radar in imaging resolution, and is more and more used in civil and military fields such as ground sensing, remote sensing and so on. However, due to the limitation of laser power and receiving sensitivity, there is a big gap between the operating range of laser radar and the traditional microwave radar, so increasing the range of action has become a hot spot in the field of laser radar. The pulse compression technique has great potential in improving the working range. Therefore, the performance analysis and simulation of the surface acoustic wave pulse compression lidar system have high theoretical value and practical application value. In this paper, the characteristics of time-wideband product of lidar system are analyzed firstly, and the pulse compression principle and process of laser radar pulse compression with wide-time-wideband product are explained, and the principle and process of pulse compression of laser radar with LFM signal are given. The characteristics of LFM lidar receiver using pulse compression scheme are obtained. The receiver has the advantages of narrow pulse width and high peak power, and meets the requirements of long range and high range resolution of lidar. Based on the principle of pulse compression, a linear frequency modulation pulse laser radar system based on acoustooptic pulse compression is designed in this paper. The working process of linear frequency modulated pulse laser radar system with acoustooptic pulse compression is analyzed in detail. The target distance equation and the relative relation between the distance equation and noise are obtained. Secondly, according to the principle of LFM pulse compression lidar, the matched filter simulation of LFM pulse compression lidar is studied. The linear correspondence between the range variation of target and the change of output correlation peak is obtained by numerical simulation, and the feasibility of ranging lidar system based on acoustooptic correlator is proved. Finally, the signal processing of LFM laser radar based on acoustooptic pulse compression is studied, the design scheme of the system is improved, and the simulation model of pulse compression laser radar system is established. On the basis of this model, the performance index of the system is studied, and an important conclusion is obtained that the signal-to-noise ratio of lidar system can be effectively improved and the detection range of the system can be significantly improved by using pulse compression technology.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN958.98

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