基于知识辅助的雷达波形设计算法研究

发布时间：2018-07-01 12:13

本文选题：知识辅助 + 波形设计　；参考：《电子科技大学》2017年博士论文

【摘要】：现代雷达往往工作在复杂的电磁和地理环境中,对环境的适应能力很大程度上决定了雷达探测能力。通过利用电磁和地理环境知识,动态调整雷达发射波形(组),可以有效提高雷达探测性能。因此,本文主要研究了基于频谱兼容,电子对抗以及海面多径三种环境知识辅助下的自适应波形设计,主要贡献如下:1.针对拥挤电磁环境中雷达与其他辐射源的频谱兼容问题,提出了基于模板匹配的TFA相位编码波形设计算法,利用电磁环境频谱信息建立功率谱模板,通过迭代使波形功率谱逐步逼近模板,实现了雷达与其他辐射源的频谱兼容,同时具有优良的自相关旁瓣特性。该算法相比传统的SCAN算法具有性能好,计算时间小的优势。考虑到设计波形的模糊函数特性约束,提出了基于SDP与随机算法的QPSC波形设计算法,利用电磁环境频谱信息,通过对相位编码波形回波信号信噪比与频谱兼容能力联合优化问题的松弛与还原,实现了雷达在频谱拥挤环境下与其他电磁辐射源的频谱兼容,使雷达信噪比接近理论极限。2.针对速度欺骗干扰抑制问题,分别提出了三种慢时间相位编码算法:膨胀遗传算法,频域投影消除法以及功率谱模板法。基于对干扰信号的识别与参数估计信息,设计针对该干扰的慢时间相位编码波形,在设定多普勒频率范围内具有很高的干扰抑制比。STFA的计算时间比SCAN,EBGA,SPE算法降低至少2个数量级,且干扰抑制水平高于其他三种算法约70 dB。3.针对多种电磁欺骗干扰环境下的目标探测问题,提出了基于PRI序列设计的干扰抑制方法,基于欺骗干扰类型的知识辅助信息,通过设计PRI序列,使干扰信号分散在不同的距离单元,并避开真实目标所在的距离单元,有效抑制了多种电磁欺骗干扰,提高了目标回波信干燥比。4.针对海面低空目标探测性能受多径效应影响的问题,建立了多径效应物理模型,分析了环境因素及物理因素对多径效应的影响,提出了基于海面环境信息辅助的频率分集和频率跟踪波形设计方法,实现了复杂海面环境下雷达探测性能的优化,相比传统的频率分集或同载频波形组具有全局更优的探测性能。以上工作,已通过仿真实验验证,基于知识辅助设计的波形可以有效提高复杂环境下雷达的目标探测性能。
[Abstract]:Modern radar often works in complex electromagnetic and geographical environment, and its adaptability to environment determines radar detection ability to a great extent. By using the knowledge of electromagnetic and geographical environment, the radar detection performance can be effectively improved by dynamically adjusting the radar transmitting waveform (set). Therefore, this paper mainly studies adaptive waveform design based on spectral compatibility, electronic countermeasure and sea surface multi-path knowledge. The main contributions are as follows: 1. Aiming at the compatibility between radar and other emitter in crowded electromagnetic environment, a design algorithm of TFA phase coding waveform based on template matching is proposed, and the power spectrum template is established by using spectrum information of electromagnetic environment. By iterating the waveform power spectrum into the template, the spectrum compatibility between radar and other emitter sources is realized. At the same time, it has excellent autocorrelation sidelobe characteristics. Compared with the traditional scan algorithm, this algorithm has the advantages of better performance and less computation time. Considering the fuzzy function characteristic constraint of the design waveform, a QPSC waveform design algorithm based on SDP and stochastic algorithm is proposed, which utilizes the electromagnetic environment spectrum information. Through the relaxation and reduction of the joint optimization of the signal-to-noise ratio (SNR) and spectral compatibility ability of the phase-coded waveform echo signal, the spectral compatibility of radar with other electromagnetic radiation sources in the crowded spectrum environment is realized, and the SNR of the radar is close to the theoretical limit of .2. Three slow time phase coding algorithms are proposed for the suppression of speed deceptive interference: expansion genetic algorithm, frequency domain projection elimination method and power spectrum template method. Based on the information of identification and parameter estimation of the interference signal, the slow time phase coding waveform for the interference is designed. The calculated time of the STFA with high interference suppression ratio in the range of Doppler frequency is at least 2 orders of magnitude lower than that of the SCANN EBGAN SPE algorithm. The interference suppression level is higher than that of the other three algorithms about 70dB.3. Aiming at the problem of target detection in many kinds of electromagnetic deception jamming environment, the interference suppression method based on PRI sequence design is proposed. Based on the knowledge auxiliary information of deception jamming type, the PRI sequence is designed. The jamming signal is dispersed in different range units, and the range unit of the real target is avoided, which effectively suppresses many kinds of electromagnetic deception interference and improves the echo signal drying ratio of the target. Aiming at the problem that the detection performance of low altitude target is affected by multipath effect, a physical model of multipath effect is established, and the influence of environmental and physical factors on multipath effect is analyzed. A design method of frequency diversity and frequency tracking waveform based on sea environment information is proposed to optimize radar detection performance in complex sea environment. Compared with the traditional frequency diversity or the same carrier wave set, the detection performance is better globally. The above work has been verified by simulation experiments. The waveform based on knowledge aided design can effectively improve the target detection performance of radar in complex environment.
【学位授予单位】：电子科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN974

【参考文献】