基于机动平台的延时多普勒测高技术研究

发布时间：2019-02-14 06:59

【摘要】：雷达高度表是飞行器中最重要的微波遥感器之一,在科学研究和经济生活等方面都有重要的用途。随着电子干扰技术的进步,强干扰下雷达信号的检测也成了当前的研究热点。近年来延时多普勒测高技术已成功应用于各种卫星上,已有的实验表明该算法不仅能够提高大大提高雷达在噪声干扰下的检测能力而且提高雷达高度表的距离分辨能力。本文采用MATLAB仿真分析的办法对延时多普勒测高算法进行了深入的研究,提出了基于大机动平台的延时多普勒算法。本文简单介绍了脉冲雷达高度表的基本理论,对适用于延时多普勒技术算法的信号形式进行分析仿真,仿真结果表明线性调频信号更适合延时多普勒算法。从SAR成像的距离徙动校正研究出发,对星载延时多普勒测高算法的进行仿真分析,为机动平台的延时多普勒算法奠定了基础。本文分析机动平台与星载平台的差异以及这些差异对信号处理检测算法所带来的影响。根据运动轨迹和观察对象的变化,计算出在新模型下需要进行延时补偿的距离,并给出基于匀加速俯冲入射模型下的延时多普勒算法。针对新运动模型下的算法,本文在MATLAB上进行了仿真分析,仿真结果表明通过延时多普勒算法,回波的脉冲前沿上升更快,回波峰值能量更高,距离分辨率更好。通过蒙特卡洛仿真统计分析发现延时多普勒补偿后能比补偿前提高8-9dB的检测能力。
[Abstract]:Radar altimeter is one of the most important microwave remote sensors in aircraft. It has important applications in scientific research and economic life. With the progress of electronic jamming technology, radar signal detection under strong jamming has become a hot topic. In recent years, delayed Doppler altimetry has been successfully applied to various satellites. Experiments show that the proposed algorithm can not only improve the detection ability of radar under noise interference, but also improve the range resolution of radar altimeter. In this paper, the delayed Doppler altimetry algorithm is deeply studied by means of MATLAB simulation analysis, and a delayed Doppler algorithm based on large maneuvering platform is proposed. In this paper, the basic theory of pulse radar altimeter is briefly introduced, and the signal form suitable for delay Doppler technique is analyzed and simulated. The simulation results show that the linear frequency modulation signal is more suitable for delay Doppler algorithm. Based on the range migration correction of SAR imaging, the algorithm of spaceborne delay Doppler altimetry is simulated and analyzed, which lays a foundation for the delayed Doppler algorithm of maneuvering platform. This paper analyzes the difference between mobile platform and spaceborne platform and the influence of these differences on signal processing and detection algorithm. According to the changes of motion trajectory and observed objects, the distance needed to be compensated for delay in the new model is calculated, and the delayed Doppler algorithm based on uniform acceleration subduction incidence model is presented. The simulation results on MATLAB show that the pulse front of the echo rises faster, the peak energy of the echo is higher and the range resolution is better by using the delayed Doppler algorithm. Through Monte Carlo simulation and statistical analysis, it is found that delayed Doppler compensation can improve the detection ability of 8-9dB compared with that before compensation.
【学位授予单位】：中国工程物理研究院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN957.51

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