基于微波探测雷达的冰层厚度反演算法的研究与实现

发布时间：2018-01-10 06:00

本文关键词：基于微波探测雷达的冰层厚度反演算法的研究与实现　出处：《电子科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：海洋占据着全球面积的71%,轻微的变化都可能给人类社会和全球气候带来很大的影响。海冰是海洋的重要组成部分,是海洋环境变化的主要因素之一,因此对海冰的探测一直是海洋探测领域的一个研究重点。由于海冰本身结构复杂,相比其他海洋探测领域海冰厚度探测技术发展的比较缓慢,导致世界各国对冰层厚度探测系统的需求都非常迫切。在研究了国内外的各种冰层探测技术及其优缺点的基础上,针对我国沿海地区薄冰的特点,项目组设计完成了FMCW制式的冰层探测系统,本文主要的研究内容是雷达系统的冰层厚度反演算法的研究与实现。针对上面介绍的研究内容,在研究和改进冰层厚度反演算法过程中,本文分析与总结了系统在实际应用中存在的问题并给出了相应的解决方案:为了确定雷达系统探测周期的起始时刻点以获取有效的信号数据和消除探测周期拐点处失真信号对结果的影响,设计了适用于本系统的信号预处理方案;针对VCO线性度问题,采用subband算法进行软件矫正;针对FFT的栅栏效应,采用FFT-CZT联合算法提升探测精度;为了消除系统随机噪声的影响,采用小波阈值去噪方法;为了优化最终结果的显示效果,在数据处理时做了去低频杂波、加窗以及均值滤波等手段。在此基础上,本文设计完成了一套基于FMCW测距原理的探冰雷达仿真系统,并利用该仿真系统初步验证了冰层厚度反演算法的有效性和准确性。同时,以上述FMCW雷达系统和相关冰层厚度反演算法为基础,针对冰层截面探测的具体应用,本文还创新性的提出了将FMCW测距原理与SAR成像原理相结合的算法,成功提高了方位向分辨率并实现了冰层截面成像的功能。同时根据上述应用于冰层截面探测的FMCW-SAR算法,本文设计了相应的仿真系统。该仿真系统中加入了冰层的物理特性对电磁波的影响,最终得到了两点和多点的成像效果图,初步验证了FMCW-SAR算法应用到冰层截面成像时的有效性和准确性。
[Abstract]:The ocean occupies 71% of the area of the world, slight changes can bring great influence to the human society and the global climate. Sea ice is an important part of the ocean, is one of the main factors of the environment change, so the detection of sea ice has been a research focus in the field of marine exploration. Because the sea ice structure is very complicated, compared the other field of marine exploration of sea ice thickness detection technology development is relatively slow, resulting in the world of ice thickness detection system needs are very urgent. Based on studying various domestic and international ice detection technology and its advantages and disadvantages. According to the characteristics of ice in the coastal areas of China, the project team completed the design of FMCW standard ice detection system and the main content of this paper is the research and implementation of ice thickness inversion algorithm of radar system. According to the research described above, the research and Reform In the process of ice thickness inversion algorithm, this paper analyses and summarizes the existing problems in the practical application of the system and gives the corresponding solutions: in order to determine the radar system detection cycle starting point to obtain the signal data effectively and eliminate the detection cycle inflection point signal distortion influence on the results, the design is suitable for signal the pretreatment program of the system; according to the linearity of VCO, using subband algorithm for software correction; fence effect of FFT, combined with FFT-CZT algorithm to enhance the detection accuracy of the system; in order to eliminate the effect of random noise, the wavelet threshold denoising method; in order to show the effect of optimization result, when processing data to do low-frequency clutter, window and mean filtering method. On this basis, this paper designs an ice penetrating radar simulation system based on FMCW ranging principle, and The simulation system validates the validity of the ice thickness inversion algorithm and accuracy. At the same time, the FMCW radar system and the ice thickness inversion algorithm is based on the specific application of ice detection section, this paper also puts forward the innovation of the FMCW ranging principle and the principle of the SAR algorithm which combines the improved success azimuth resolution and ice section imaging function. At the same time according to the FMCW-SAR algorithm for ice section detection, this paper designed the corresponding simulation system. The simulation system is added to the influence of physical properties of ice on the electromagnetic wave, finally got two and more of the imaging effect, verified FMCW-SAR the ice section imaging algorithm is applied to the validity and accuracy.

【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH766

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