Performance analysis of radar antenna systems

If modern airborne radar systems are to function properly, the radar antenna radiation patterns must meet certain specifications. Until recently, most radar antennas were designed and tested in a clean antenna environment, i.e., there is no near field scattering from host structures or radome effects. However, these higher order effects are the matter of increasing concern with added performance demands in the ever-increasing jammer and clutter interference environments. We investigated the capabilities and limitations of currently available analysis techniques and computer codes for installed performance of airborne radar antenna systems. Then we developed an extended ray-optical technique that could predict total installed performance of airborne radar antenna systems, i.e., the near field scattering from aircraft structures and radome effects. The new analysis technique utilized a ray-tracing method in both airframe and radome simulation. Thus, it can efficiently predict the total installed performance of large radar antenna systems on an aircraft structure     

Detection of Target Multiplicity Using Monopulse Quadrature Angle

The feasibility of using the indicated quadrature angle of arrival of a monopulse radar to discriminate a single target from multiple targets, separated in angle within a radar resolution cell, is investigated. The analysis is performed for steady (fixed) and Rayleigh fluctuating targets which cover a broad range of target characteristics. In both cases, the interfering signals due to noise and clutter in the sum and difference monopulse channels are assumed to be independent, zero-mean Gaussian processes. Detection and false alarm probabilities are evaluated analytically and the receiver operating characteristics are obtained for both fixed and fluctuating target cases. It is shown that multiple targets can be discriminated from a single target condition by integrating the indicated monopulse quadrature angle of arrival from several independent pulses. It is also shown that the probability of detecting multiple targets increases as the fluctuation in the target radar cross section decreases, approaching the fixed amplitude case in the limit.     

ESM对2D雷达引导性能分析

 对于由 ESM和雷达组成的多传感器系统,分析和推导了用 ESM对 2 D雷达成功引导的概率解析表示式,为求解成功引导概率提供了依据;研究了 ESM对 2 D雷达成功引导概率随一些特征参数的变化规律,并得出了 4个特性;在多种情况下进行了成功引导概率的数值计算,验证了成功引导概率的一些变化规律,并得出了一些有意义的结论,从而对研究和设计同地配置的 ESM对雷达引导系统具有一定的参考价值。     

Space-time registration of radar and ESM using unscented Kalman filter

Space and time alignments are the prerequisites for the successful fusion of multiple sensors. A space-time registration model is proposed to estimate the system biases and to perform time synchronization together for mobile radar and electronic support measure (ESM) systems. A space-time registration model for radar and ESM is first developed, and an unscented Kalman filter (UKF) is proposed to estimate the space-time biases and target states simultaneously. The posterior Cramer-Rao bounds (PCRBs) are derived for the proposed UKF registration algorithm for ESM detection probability less than or equal to one. Theoretical analyses are performed to evaluate the accuracy and robustness of the proposed method. Computer simulations show that the UKF registration algorithm is indeed effective and robust for different radar and ESM tracking scenarios.     

An approach to radiated testing of installed airborne Doppler radarwith weather/windshear detection capability

Numerous documents were reviewed to verify radar parameters needed to analyze and present the tester concept described herein. The weather and windshear models defined use the identical criteria established for the Doppler radar in terms of F-factor. The basic concept of the tester is to transmit coherent simulated radar returns in response to the airborne radar's transmission while mounted on a tripod in the far field of the radar when parked on the ramp. The varying amplitude of the received radar pulses are analyzed and put into memory as the tester antenna is illuminated by the scanning main beam and side lobes of the radar's antenna patterns. The tester controls the power of its outputted simulated radar returns in inverse relation to the power of the received radar pulses. These simulated radar returns, outputted into the main beam and/or side lobes of the scanning radar antenna, are interpreted by the radar system as received in the main lobe. The tester transmissions, incorporating microburst, storm and gust front models, previously defined, can thereby test the aircraft radar system performance in various hazard environments. The tester is designed to: verify operational performance of the radar; demonstrate installed radar performance; verify crew reports and minimize radar or LRU's removal for maintenance; test before and after a repair; and verify radome effects on radar performance     

改进 K-均值算法在雷达辐射源信号预分选中的应用

雷达辐射源信号分选是电子对抗领域一个关键技术,随着电子技术的发展,电磁环境日趋复杂,信号分选的难度越来越大,在这样的条件下,我们应该寻求新的解决问题的方法.本文首先概述了雷达辐射源信号分选意义、系统组成和分选流程,然后介绍了改进 K-均值算法.为了有效实现信号分选,提出了基于改进K-均值算法的信号分选方法,该方法可对到达角、载频和脉宽参数进行分选.最后进行了仿真实验,结果表明该方法实现简单,分选效果较好     

VHF地空数据链网关信息处理模式分析

VHF数据链网关信息处理模式直接影响系统的实时性,采用排队论模型详细分析了两种信息处理模式对系统实时性的影响,进行了计算机仿真,通过分析仿真结果,得到了适合的信息处理模式。     

修正极坐标系下雷达与ESM航迹对准关联

研究了存在系统误差时修正极坐标系(MPC)下的雷达与电子支援措施(ESM)航迹关联问题。系统误差导致MPC下雷达和ESM的角度估计产生偏移,而对角度变化率、距变率与距离的比值(ITG)的估计影响不大;结合非中心卡方分布的知识,分析了雷达与ESM的测量误差对非中心参数和正确关联概率的影响;提出了一种基于积分重合度的雷达与ESM航迹对准关联算法。首先将雷达与ESM的目标映射到角度-角度变化率空间,分别得到了雷达与ESM的目标曲线,然后对两目标曲线求积分重合度,估计出雷达与ESM测角系统误差的偏移量,对偏移量补偿后进行雷达与ESM的航迹关联。仿真结果表明,本文所提算法能有效地提高存在系统误差时雷达与ESM正确航迹关联概率。     

CESM-a new category of radar ECCM

Radar ECCM techniques are well known. Heretofore the listed ECCM effects have generally been to counteract the effects of ECM. This approach is one of attempting to cure an illness, rather than preventing it. Modem ECM systems usually include an ESM receiver to detect the radar signal, identify it by its emission characteristics, assess its importance, select the proper ECM, and signal to initiate ECM. If the ESM receiver detection of the radar signal can be delayed/denied, or the identification be confused, either the wrong ECM may be applied, or delayed. The radar may thus not be confronted with timely, proper ECM. Radar operation may therefore be possible. This paper introduces and defines CESM, a new category of radar ECCM. There are two principles of CESM-those which delay/deny ESM receiver detection, and those which confuse/impede signal identification. Illustrative examples of CESM techniques/operating techniques are given. It is shown that many CESM techniques may have multiple roles by impeding detection, impeding identification, and also diluting effects of ECM     

智能化雷达对抗情报处理技术研究

随着雷达技术的迅猛发展,雷达信号的密度、复杂程度都大幅度提高,这就增加了雷达信号的不确定性因素。本文讨论了粗糙集理论、模糊集理论、证据理论和可能性理论等人工智能技术在雷达对抗情报处理中的应用。对雷达辐射源的型号和工作模式识别、雷达网信息以及所属平台信息的推理技术进行了探索研究,给出了研究建议。     

一种MIMO雷达幅相误差估计方法

 针对单基地相关多输入多输出(MIMO)雷达中存在的阵列幅相误差问题进行了研究。给出了单基地相关MIMO雷达的阵列模型,并提出了一种MIMO雷达幅相误差估计方法。利用发射正交信号对阵列接收信号进行匹配滤波,可分离得到类似传统阵列的"虚拟阵列",利用分时信源数据将该阵列中真实导向矢量中信源波达方向(DOA)引起的相位与幅相误差分离开,通过构造代价函数得到波达方向估计值,进而分别得到发射阵与接收阵的幅相误差的估计值,同时给出了误差引入量分析。最后通过仿真验证了该方法的有效性。本文介绍的方法简单可行,适用于任意构型MIMO雷达的幅相误差估计。     

Computational Algorithms for a Pseudo-Bayes Digital Radar Receiver

In this paper discrete likelihood ratio computational algorithms resulting from recent studies in detection theory are applied to the general radar detection problem in which it is desired to detect the presence or absence of a sinusoidal pulse with unknown time of arrival, frequency, and phase. The resulting optimum digital receiver structure isdetermined and computer simulation results presented.     

Noise Angle Accuracy of Several Monopulse Architectures

Rigorous analysis of four monopulse radar architectures has been conducted to develop the practical angle-tracking accuracy of the systems due to noise. The word ?practical? is used to imply that the systems may have range gates of arbitrary duration and may transmit pulses with arbitrarily shaped envelopes. The accuracy measure used is the mean-squared error (variance) in angle tracking. The four systems considered differ from each other according to the locations of the range gates and ?matched filters? in their architectures.     

救护直升机机载救护装备优化配置研究

基于救护直升机勤务功能及作业能力,研究救护直升机机载装备的优化配置。首先根据救护直升机的勤务需求,确定救护直升机机型装备的品种,然后采用排队论方法研究救护直升机机载装备的数量配置。结果表明排队论方法能够为救护直升机机载装备数量配置提供一个有效的、客观的科学手段,研究结果可为救护直升机研制提供依据。     

PASSIVE LOCATION AND ACCURACY ANALYSIS USING TDOA INFORMATION OF MULTI-STATIONS

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Radar Handbook, 3rd Edition (M.I. Skolnik, Ed; 2008) [Book Review]

Thirty eight radar experts contribute to this edition, which includes six completely new chapters on the following topics: ground penetrating radar; remote sensing with radar on satellites; multifunctional radar systems for fighter aircraft (MFAR); digital signal processing for radar; civil marine radar; and propagation. Each chapter contains references, ranging from 10 to 197, with a median of 71. The index runs 18 pages printed in double columns, but is not necessarily complete. Some topics, such as MIMO radar and long range radars to track satellites and ballistic missiles, will have to wait for a 4th edition. This text is the most authoritative, broadest, and deepest single volume on radar. The emphasis is on real world performance and real hardware that has been tested and works successfully in the real world, and the physics relevant to radar systems, as well as radar system engineering cost tradeoffs.     

应用卡尔曼滤波的机载雷达跟踪系统

本文论述将滤波理论应用于机载雷达中对单个目标进行距离、速度、方位角和高低角跟踪的多环反馈系统。首先根据目标和天线的相对运动建立控制四坐标跟踪环所需的状态矢量微分方程,然后推导相应的非线性滤波算法。最后给出计算机的模拟结果。计算机模拟的结果清晰地说明采用最佳滤波的系统性能比通常的有很大改善,并且这种瞄准轴坐标系的最佳系统对目标的随机机动是不灵敏的。 本文所讨论的方法和得出的结论可以延用到地面雷达、舰载雷达以及其他有源和无源的跟踪系统。     

Detecting the Presence of Target Multiplicity

A method is discussed for detecting the presence of multiple targets in the radar antenna beam. It is assumed that the targets are unresolvable in range, Doppler, and angle using conventional monopulse resolution techniques. The basic approach taken is a generalization of the "quadrature" method, with significantly enhanced performance in the case when multiple pulses are integrated into a single solution. Detection and false alarm probabilities are derived analytically and the receiver operating characteristics are graphed. This study was performed for application to angle processing in a frequency agile automatic tracking radar, but the underlying concept is general and has applications outside this area.     

基于模糊条件证据理论的雷达辐射源识别

基于不确定证据与不确定先验知识和谐的思想,利用模糊条件证据理论,给出一种融合模糊先验知识的新的雷达辐射源识别方法。首先,把雷达辐射源模糊观测数据表示为Dempster-Shafer（D—S）证据的随机集形式;然后,计算观测证据与模糊先验知识之间的和谐度;最后,利用模糊条件证据理论把需要融合的证据进行组合。这种方法可充分利用各种不同来源的信息,从而提高雷达识别的可靠性。     

基于时空结构的双基MIMO雷达多维参数联合估计

为了充分利用目标的时域特性来改善双基多输入多输出(MIMO)雷达波达方向(DOA)和离波方向(DOD)的估计性能,探讨了双基MIMO雷达在时-空模型下的多维参数联合估计问题。针对慢动目标,基于多维旋转不变技术信号参数估计(ESPRIT)算法,同时利用时域相邻两级延迟包含的时间相位差、发射阵列相邻阵元包含的空间相位差以及接收阵列相邻阵元包含的空间相位差作为旋转因子,形成旋转不变子空间,再根据矩阵、矩阵的特征值及特征值对应的特征向量三者之间的关系解决了参数配对问题,实现了三维参数联合估计。该方法在信噪比低、积累脉冲数少时,目标的DOA与DOD估计性能比不利用时域特性时有明显改善。仿真结果验证了本方法的有效性。