星载SAR压制式干扰与抗干扰技术研究

发布时间：2018-11-22 18:59

【摘要】：星载SAR作为当前最为主要的雷达系统平台之一,其在军事应用中一直具有重要的战略意义,因此星载SAR对抗技术研究具有重要应用价值。压制式干扰及抗干扰是星载SAR对抗研究中重要组成部分,并且关于该干扰方式的研究时间较早,因此压制式干扰理论相对比较成熟,但由于技术的不断进步,传统关于压制式干扰的一些观点变得不再适用。本文在国家863前期项目的支持下,对压制式干扰对抗技术进行了以下研究:本论文在干扰对抗研究开始之前分析了当前星载SAR对抗研究现状及其理论研究成果,为研究星载SAR压制式干扰与抗干扰技术提供了理论基础。首先,本文研究了目前星载SAR干扰对抗的需求,梳理了当前国内外压制式干扰技术的主要研究成果,分析了压制式干扰存在的问题和难点。从星载SAR回波模型及成像技术角度着手,对压制式干扰理论进行了新的研究,其一从功率上论证了星载SAR干扰的可行性,对早期关于压制式干扰的观点与认识进行修正;其二,基于干信比需求分析,对星载SAR压制式干扰干信比提出更低要求,并通过仿真实验证实了观点正确性。然后,研究了基于成像前和成像后的抗压制式干扰的方法。成像前抗干扰主要是利用干扰信号与回波信号在时域以及频域上的差异性来进行干扰抑制,方法有:对于高频脉冲干扰,根据其被干扰信号段幅度与未被干扰信号段幅度不同而进行干扰抑制;对于相参压制式干扰,利用多通道对消方式,根据干扰机到多个天线接收机距离不同而产生相位差,从而弥补相位差实现干扰对消;其次简单的描述了系统层面的抗干扰手段,双基SAR来规避干扰信号进入接收机。此外还通过仿真实验验证了,对于连续波噪声压制干扰,由于其在各个变换域与目标信号重合较多,其干扰抑制难度大,待研究新的抗干扰方法。成像后抗干扰方法主要是研究了基于图像域的抗压制式干扰方法。由于压制式干扰信号与目标回波信号在图像域存在统计特性差异,因此可采用独立分量分析的方法和基于峭度准则将两者分离开,实现干扰抑制。最后通过最小均方误差和干信比评估准则,对ICA处理后SAR图像与常规滤波方法结果作对比,得出ICA方法在图像域对干扰的抑制具有更好效果的结论。
[Abstract]:As one of the most important radar system platforms, spaceborne SAR has always been of strategic significance in military applications, so the study of spaceborne SAR countermeasures has important application value. Suppression jamming and anti-jamming are important parts of spaceborne SAR countermeasure research, and the research time of the jamming mode is earlier, so the theory of suppression jamming is relatively mature, but due to the continuous progress of technology, Some of the traditional ideas about repressive interference are no longer applicable. With the support of the National 863 Prophase Project, this paper makes the following research on the suppression jamming countermeasure technology: this paper analyzes the current research status and theoretical results of spaceborne SAR countermeasures before the study of jamming countermeasures begins. It provides a theoretical basis for studying the suppression jamming and anti-jamming technology of spaceborne SAR. Firstly, this paper studies the demand of spaceborne SAR jamming countermeasures, combs the main research achievements of suppression jamming technology at home and abroad, and analyzes the existing problems and difficulties of suppression jamming. From the angle of spaceborne SAR echo model and imaging technology, a new research on suppression jamming theory is carried out. Firstly, the feasibility of spaceborne SAR jamming is demonstrated from power point of view. Secondly, based on the requirement analysis of dry signal ratio, a lower requirement is put forward for spaceborne SAR suppression jamming dry signal ratio, and the correctness of the viewpoint is verified by simulation experiments. Then, the method of anti-compression interference based on pre-imaging and post-imaging is studied. The anti-jamming before imaging mainly uses the difference between the interference signal and the echo signal in the time domain and frequency domain to suppress the interference. The methods are as follows: for the high-frequency pulse interference, The interference suppression is carried out according to the difference between the amplitude of the disturbed signal segment and that of the undisturbed signal segment. For coherent suppression interference, the phase difference is produced according to the different distance between the jammer and the antenna receiver by using the multi-channel cancellation mode, which makes up the phase difference to realize the interference cancellation. Secondly, it simply describes the system level of anti-jamming means, bistatic SAR to avoid interference signal into the receiver. In addition, the simulation results show that for the continuous wave noise suppression interference, it is difficult to suppress the interference because it overlaps with the target signal in each transform domain, so a new anti-jamming method is needed to be studied. The main method of anti-jamming after imaging is to study the anti-compression jamming method based on image domain. Because there are statistical differences between the suppression jamming signal and the target echo signal in the image domain, the independent component analysis (ICA) method and the kurtosis criterion can be used to separate the two signals to achieve interference suppression. Finally, through the minimum mean square error and dry signal ratio evaluation criterion, the results of SAR image after ICA processing are compared with the results of conventional filtering method, and the conclusion that ICA method has better effect on the suppression of interference in image domain is obtained.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN974

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