成像雷达系统的建模与仿真

发布时间：2018-06-26 00:41

本文选题：合成孔径雷达 + 成像雷达系统　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：现如今随着合成孔径雷达(Synthetic Aperture Radar,SAR)成像算法的研究越来越深入,SAR成像雷达逐步成为机载、星载的标准传感器模式,在民用及军事领域得到了广泛的应用。目前国内SAR成像仿真主要是基于Matlab平台,重点研究各种成像处理算法。而对于SAR系统仿真体系架构,以及PD(Pulse Doppler)雷达、SAR、STAP(Space-time Adaptive Processing)等多模式雷达联合仿真国内尚未大量研究。针对目前国内仿真领域存在的上述问题,本文基于标准化平台,建立了一套标准的、扩展性强的、复用程度高的SAR雷达仿真模型。利用这套模型,可快速形成各种SAR仿真系统,仿真不同运动速度、不同角度等约束条件下成像系统的相关性能指标。本文的主要工作如下:首先,本文提出了基于软件结构化为核心的成像系统设计方案。给出了软件框架的具体结构,它的核心思想是总线机制和标准化接口,采用XML技术和Amardillo穿山甲线性代数库实现了标准化模型和层次化模型的设计。然后,探讨了时域和频域两种回波模拟的主要算法。时域算法通过对目标散射特性、时间延迟和多普勒等信息的处理直接生成回波模拟信号;频域算法利用距离多普勒(Range-Doppler,RD)、CS(Chirp Scaling)成像逆处理生成所需回波信号。根据系统参数使用C/C++编写回波生成代码,并在软件平台上搭建回波计算模型,最后与Matlab的仿真结果比对验证模型正确性。其次,对RD处理模型的功能模块进行建模与仿真,对正侧视情况以及斜视30度情况下的RD成像处理的具体步骤进行分析,并给出算法处理流程。利用回波计算模块生成的回波信号实现距离多普勒算法处理,根据系统参数使用C/C++编写代码构建距离多普勒算法模块,并在软件平台上搭建RD处理流程模型,通过仿真验证了模型的正确性。最后,对CS处理模型的功能模块进行建模与仿真。CS成像算法可看成是RD成像算法的优化和改进。CS成像算法对相位补偿的考虑更加精确,使得方位分辨率得到有效改善。CS成像算法的处理关键在于利用线性变标实现距离徙动校正。利用回波计算模块生成的回波信号实现Chirp Scaling处理,根据系统参数使用C/C++编写代码构建Chirp Scaling算法模块,并在软件平台上搭建CS处理流程模型,通过仿真验证了模型的正确性。
[Abstract]:Nowadays, with the research of synthetic Aperture radar (SAR) imaging algorithm, SAR imaging radar has gradually become airborne, spaceborne standard sensor mode, and has been widely used in civil and military fields. At present, SAR imaging simulation is mainly based on Matlab platform, focusing on various imaging processing algorithms. However, there is not much research on SAR system simulation architecture and multi-mode radar simulation, such as PD (Pulse Doppler Radar) STAP (Space-time Adaptive processing). Aiming at the above problems in the domestic simulation field, a set of standard, extensible and reusable SAR radar simulation model is established based on the standardized platform. Using this model, various SAR simulation systems can be quickly formed, and the relevant performance indexes of the imaging system can be simulated under different moving speed and different angle constraints. The main work of this paper is as follows: firstly, a design scheme of imaging system based on software structure is proposed. The concrete structure of the software framework is given. Its core idea is bus mechanism and standardized interface. The standardized model and hierarchical model are designed by using Amardillo technology and Amardillo pangolin linear algebra library. Then, two main algorithms of echo simulation in time domain and frequency domain are discussed. The time domain algorithm directly generates the echo analog signal by processing the target scattering characteristics, time delay and Doppler information, and the frequency domain algorithm uses the range Doppler (Rd) / CS (Chirp scaling) imaging inverse processing to generate the needed echo signal. According to the parameters of the system, C / C is used to write the code of echo generation, and the echo calculation model is built on the software platform. Finally, the simulation results of Matlab are compared to verify the correctness of the model. Secondly, the function module of Rd processing model is modeled and simulated, and the specific steps of Rd imaging processing are analyzed under the condition of positive side view and 30 degrees strabismus, and the algorithm processing flow is given. The range Doppler algorithm is processed by echo signal generated by echo calculation module. According to the system parameters, C / C code is used to build the range Doppler algorithm module, and the Rd processing flow model is built on the software platform. The correctness of the model is verified by simulation. Finally, the modeling and simulation of the functional module of CS processing model. CS imaging algorithm can be regarded as the optimization of Rd imaging algorithm and the more accurate consideration of phase compensation by improved .CS imaging algorithm. The key to improve the azimuth resolution of the .CS imaging algorithm is to use linear scaling to achieve range migration correction. Chirp scaling processing is realized by echo signal generated by echo computing module. Chirp scaling algorithm module is constructed by C / C code according to system parameters, and CS processing flow model is built on software platform. The correctness of the model is verified by simulation.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN958

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