共查询到19条相似文献,搜索用时 171 毫秒
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一种基于广义似然比检测的雷达目标识别新方法 总被引:3,自引:3,他引:0
为了实现发射周期内目标的实时识别,首先建立了E脉冲激励下目标回波的二元假设检验模型,在此基础上导出了识别目标的广义似然比检测量,并从理论上给出了计算目标识别概率的解析表达式.基于数值计算的三种细导线目标散射场数据的仿真实验以及理论计算结果表明,本文提出的基于广义似然比检测目标识别新方法的实验目标识别性能与其理论计算值是一致的,且其目标识别性能优于直接发射E脉冲目标识别方法. 相似文献
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基于改进概率数据关联滤波的红外小运动目标跟踪 总被引:1,自引:0,他引:1
在跟踪弱小运动目标过程中,低信噪比和高虚警率使得即使是在波门内也存在较多的虚假目标,加大目标识别的不确定性,降低跟踪的可靠性和精度。该文分析了红外成像系统中目标信号特点,根据概率数据关联滤波的思想,提出了一种基于目标幅度连续性和运动一致性的弱小目标跟踪识别方法,重点比较了极大似然-概率数据关联滤波和改进算法的目标识别与跟踪性能。理论分析和实验结果表明,该方法较大程度上减少了弱小目标跟踪过程中测量点与航迹关联的不确定性,提高了目标识别与跟踪性能。 相似文献
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针对低信噪比条件下S模式应答信号检测概率低、虚警概率高的问题,提出一种基于数据包检测、单脉冲匹配滤波和报头多脉冲检测等三次相关检测的增强识别方法。该方法首先利用数据包相关检测得到数据包位置,从而确定报头脉冲的检测门限;然后利用单脉冲匹配滤波对信号进行降噪处理,确定脉冲位置;最后估计脉冲幅度和噪声功率,利用多脉冲相关检测识别信号报头。通过这三次相关处理,该识别算法可提高S模式应答信号的准确识别率。理论推导了检测概率的数学表达式,通过计算机仿真,在期望虚警概率下,本文方法基本达到了理论检测概率,同时对比了本文方法与传统的直接匹配滤波法、脉冲前沿检测法、基带归一化互相关法的识别性能,验证了本文算法性能的优越性。 相似文献
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雷达目标识别技术综述 总被引:18,自引:7,他引:18
针对雷达自动目标识别技术进行了简要回顾。讨论了目前理论研究和应用比较成功的4类目标识别方法:基于目标运动的回波起伏和调制谱特性的目标识别方法、基于极点分布的目标识别方法、基于高分辨雷达成像的目标识别方法和基于极化特征的目标识别方法,同时讨论了应用于雷达目标识别中的4种模式识别技术:统计模式识别方法、模糊模式识别方法、基于模型和基于知识的模式识别方法以及神经网络模式识别方法。最后分析了问题的可能解决思路。 相似文献
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针对收发分时体制数字射频存储器(DRFM)干扰方式,提出一种能有效对抗此方式的多脉冲雷达信号发射样式。该方式在雷达接收机中分多路进行匹配滤波,利用干扰机收发分时体制,无论其转发接收到的任何一个脉冲,雷达方总能利用另一路正确检测目标。经理论分析与仿真表明,该方法简单有效。 相似文献
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Blanco D. Ruiz D.P. Alameda E. Carrion M.C. 《Antennas and Propagation, IEEE Transactions on》2004,52(5):1348-1350
This communication proposes an E-pulse-based scheme for radar target discrimination that provides asymptotically correct results for any level of additive white noise contaminating the radar signal. After multiple sampling of the signal dispersed by the target, it is analytically shown that the cross correlation between the output signals of the E-pulse designed for the standard target, corresponding to two different sampling periods, is asymptotically , regardless of the amount of contaminating noise. The results obtained by simulation have allowed us to propose a discrimination criterion that produces better results than the original E-pulse technique at very low signal-to-noise ratio (SNR) levels. 相似文献
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An automated E-pulse scheme for target discrimination was initially presented by Ilavarasan et al. (1993) without an analytic performance evaluation. Assuming that target responses are contaminated with white Gaussian noise, an automated E-pulse scheme is rigorously analyzed to yield a reliable measure of performance. The discrimination performance of this automated E-pulse scheme is determined quantitatively through the use of energy discrimination numbers (EDNs). Statistics of the EDNs are evaluated analytically to derive the probability of correct identification. The probability of identification as a function of signal-to-noise ratio (SNR) is evaluated using the theoretical scattering data for all potential targets to predict the performance of the automated E-pulse scheme. These theoretical results are corroborated by direct simulation of the discrimination scheme. In addition, the probability density functions of the EDNs are presented providing new physical insights into E-pulse performance as a function of target geometries and SNR 相似文献
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Blanco D. Ruiz D.P. Alameda-Hernandez E. Carrion M.C. 《Antennas and Propagation, IEEE Transactions on》2006,54(5):1577-1585
The extinction pulse method has been proven to be a suitable method for radar target discrimination using the natural resonance annihilation concept. The standard procedure for extinction pulse (E-pulse) construction is based on an expansion on subsectional polynomials. In this paper it is proposed a new formalism for E-pulse construction using /spl beta/-splines. This formalism allows the E-pulse polynomial basis expansion to be treated in a unified theoretical framework and leads to a simplification of the original problem due to the linear nature of all the involved parameters. This new formulation has been also used to impose new conditions over the spectral contents of the E-pulses. These E-pulses constructed using the new conditions annihilate better the natural modes in the late-time radar target response, and provide a better discrimination rates than the classical scheme. 相似文献
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Ilavarasan P. Ross J.E. Rothwell E.J. Chen K.-M. Nyquist D.P. 《Antennas and Propagation, IEEE Transactions on》1993,41(5):582-588
Previous studies have demonstrated the viability of natural resonance based target discrimination using extinction pulses (E pulses) and single-mode pulses (S pulses). These studies qualitatively demonstrated the principles of resonance annihilation by forcing the interrogating pulse to have zeros at the complex natural resonance frequencies of the target. Here a quantitative scheme for evaluating discrimination using the E pulse and the S pulse is given. The performance of an automated E-pulse and S-pulse discrimination scheme is evaluated using numerically derived scattering data with varying amounts of noise 相似文献
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为解决组网雷达对目标跟踪中的量测非线性问题,提出基于最佳线性无偏估计器(BLUE)准则的融合滤波方法。建立以融合中心为原点的组网雷达对目标定位的量测方程,推导出极坐标系与球坐标系下跟踪目标的BLUE滤波模型。理论分析表明,集中式BLUE滤波架构在估计单个雷达量测转换误差统计特性的同时,还估计出雷达间量测转换误差的统计特性。因此,跟踪精度和置信度较分布式BLUE滤波方法有显著提高,计算量较其他算法也有明显优势。不同场景下的仿真分析证明:该方法在不同状态噪声水平下的表现优异,是一种很有竞争力的跟踪算法。 相似文献
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Baum C.E. Rothwell E.J. Chen K.-M. Nyquist D.P. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1991,79(10):1481-1492
The singularity expansion method (SEM) for quantifying the transient electromagnetic (EM) scattering from targets illuminated by pulsed EM radiation is reviewed. SEM representations for both induced currents and scattered fields are presented. Natural-resonance-based target identification schemes, based upon the SEM, are described. Various techniques for the extraction of natural-resonance modes from measured transient response waveforms are reviewed. Particular attention is given to the aspect-independent (extinction) E-pulse and (single-mode) S-pulse discriminant waveforms which, when convolved with the late-time pulse response of a matched target, produce null or mono-mode responses, respectively, through natural-mode annihilation. Extensive experiment results for practical target models are included to validate the E-pulse target discrimination technique. Finally, anticipated future extensions and areas requiring additional research are identified 相似文献
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Morales J.D. Blanco D.. Ruiz D.P. Carrion M.C. 《Antennas and Propagation, IEEE Transactions on》2007,55(7):2064-2072
New contributions to noncooperative radar-target discrimination using only the scattered response of conductive objects are presented in this paper. The technique studied is the extinction-pulse (E-pulse), which makes use of natural resonances as discrimination features. The E-pulse expansion using complex exponential functions as basis functions is proposed, obtaining new E-pulses with characteristics completely different from those in the literature. Specifically, a weighting factor is added to modulate the exponential frequency, providing E-pulses with better discrimination capability. Numerical results achieved in the discrimination between thin straight wires of different lengths show that the proposed exponential E-pulses improve the discrimination results with respect to other types of E-pulses in the literature. 相似文献
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Rothwell E.J. Kun-Mu Chen Nyquist D.P. Ilavarasan P. Ross J.E. Bebermeyer R. Qing Li 《Antennas and Propagation, IEEE Transactions on》1994,42(9):1336-1341
A duality between the temporal late-time response and the spectral early-time response of a radar target is used to form the basis for a general E-pulse technique. Examples, using the ultrawide-band measurements of an aircraft model, reveal that E-pulse cancellation is possible both in the time domain for the late-time component and in the frequency domain for the early-time component. Applications to radar target discrimination and clutter cancellation are described, and the aspect dependence of early-time discrimination is investigated 相似文献