两部雷达部署的研究

本文研究了两部雷达联合发现目标概率 ,采用特征尺度的分析方法解决了最佳部署问题 ,得到了极其简单 ,计算量很小的关于确定最佳距离的有效公式 ,并用实际算例进行了验证     

两部雷达最佳部署问题研究

本文研究两部雷达联合发现目标概率,采用Monte Carlo法解决了最佳部署问题。     

对机载轰瞄雷达的多站协同干扰压制区计算

基于多干扰站空间功率合成理论及协同干扰理念,讨论了在各干扰站发射信号到达机载轰瞄雷达处的相位可精确设置与相位呈随机均匀分布两种情形下的干扰功率合成计算,构建了要地防空作战背景下对机载轰瞄雷达的多站协同干扰压制区计算模型,并进行了示例仿真分析。分析结果表明,与传统的计算干扰压制区的直接叠加法相比,基于空间功率合成理论的整体求值法能够获得更大的有效压制区。论文研究内容可为地对空雷达干扰效能分析评估以及地对空雷达干扰力量优化决策提供科学合理的参考依据。     

基于多目标优化的对抗反辐射导弹诱饵部署

针对目前研究部署诱饵保护地基雷达免遭反辐射导弹攻击未考虑多个目标的情况,提出了基于多目标优化的诱饵最优位置模型.首先对影响部署诱饵的各因素进行分析,并用随机仿真模型进行建模,目标是同时最大化反辐射导弹爆炸点与地基雷达以及诱饵之间距离;然后采用概率多目标模拟退火算法获得诱饵位置组合的非支配组合;根据决策者的不完全偏好信息,采用多属性效用函数,获得偏好非支配组合.最后对模型进行仿真,仿真结果表明模型的有效性.     

空管雷达的功率问题

本文首先建立计算普通雷达发射功率的数学模型,得到了理想的结果。然后讨论了圆盘假设问题,并对原始模型进行了修正,使结论更近于实际。最后对问题本身提出了一些看法,并为改进雷达发射系统提出了建议。     

多机协同欺骗组网雷达的多虚假航迹制定方法

为有效欺骗组网雷达并充分利用设备资源,对干扰机进行复用,基于传统多机协同欺骗组网雷达模型设计了一种产生更多虚假航迹的轨迹规划方法,并将变高度平面与雷达-虚假目标射线的交点作为干扰机的航迹点,突破传统模型中干扰机只能做定高飞行的弊端,使真实航迹具有多样性,令敌方更难预测其坐标位置,保证自身安全.同时从几何关系上建立干扰机处于机动状态下的组网雷达、干扰机组、虚假航迹间的数学模型,以9架干扰机产生4条虚假航迹为例给出模型求解流程.     

多无人机协同任务规划问题

研究无人机任务规划问题,从无人机侦查和轰炸两方面入手.首先,运用迭代算法求解出从基地到雷达区域边际上任一目标出入口的最短路径.在此基础上,以无人机在雷达范围内滞留时间最短,以及被探测次数最少为目标,建立多目标最优化模型.通过改进交叉算子的遗传算法找出最优侦查路径.对于轰炸任务,以无人机在雷达范围内滞留时间最短,以及轰炸总时间最短为目标,建立多目标最优化模型.采用改变惯性权重的自适应粒子群算法找出最佳轰炸路线.由于计算时间较长,本文对68个目标进行聚类分析,提出针对轰炸任务的快速算法,相较原轰炸方案,其计算效率提高80%以上.     

多无人机对组网雷达的协同干扰问题研究

在现代战场中,航迹欺骗干扰技术是针对组网雷达提出的协同干扰技术,旨在利用多架无人机在同一时刻对组网雷达中的部分雷达实施相互关联的虚假目标欺骗干扰.充分考虑了实际情况下无人机飞行模态、飞行速度、飞行高度的约束限制,对雷达的位置分布以及虚假航迹线进行可视化,并将三维空间模型投影到二维平面后进行建模分析.主要针对一个虚拟的无人机航迹欺骗干扰问题,建立时空模型,通过构建可达交互矩阵和雷达扫描算法,结合0-1整数规划,得到无人机协同飞行的最优策略.     

求时滞系统最大实部本征值的一种数值算法

时滞动力系统是一类无穷维系统,其平衡点在Lyapunov意义下的渐近稳定性可由该系统的线性化系统的无穷多个本征值的分布来确定.在一定条件下,平衡点是渐近稳定的当且仅当最大实部本征值的实部小于零.本文给出了一种计算最大实部本征值的数值算法,只需要多次计算一个与本征函数及其导数的实函数的数值积分即可.该算法易于编程计算,并且增加时滞的个数并不增加稳定性分析的困难.利用本文算法计算了一阶中立型时滞微分方程的最大实部本征值.     

多无人机协同任务策略优化

从研究多无人机协同任务的系统资源分配、任务分配、航线规划、轨迹优化等问题入手,建立了多基地多无人机协同侦察模型.针对问题,首先利用"栅格化聚拢"的思想对目标点进行过滤优化,进而对目标群和无人机基地进行了任务分配,而后结合蚁群算法、贪心算法、最短路径算法等思想,通过Matlab平台,计算出能够让无人机停留在雷达探测区域总时间最少的最优策略.     

New designs of frequency hopping sequences with low hit zone

Frequency hopping sequences have been found wide applications in various modern frequency hopping spread spectrum communications and radar systems. With potential applications to these areas such as ultra wide bandwidth time hopping code division multiple access radio systems, multi-user and sonar systems, the design of quasi-synchronous time/frequency hopping code division multiple access systems by employing low hit zone hopping sequences has attracted wide attentions. In this paper, we present three construction methods for the low Hamming correlation zone frequency hopping sequences. The parameters of these sets of frequency hopping sequences with low hit zone are new and flexible. The constructed sequences are almost optimal and optimal respectively with respect to the Peng?CFan?CLee bounds. The simplicity of this technique makes it attractive for practical use.     

基于相似度和改进雷达图的概率犹豫模糊多属性决策方法

为了解决属性权重未知的概率犹豫模糊多属性决策问题,构建基于相似度和改进雷达图的多属性决策方法。首先基于概率犹豫模糊元的信息完全度构建概率犹豫模糊集的距离测度和灰色关联系数,然后基于灰色关联理想解法定义了概率犹豫模糊集的相似度,最后根据概率犹豫模糊集的相似度和改进雷达图构建多属性决策模型,并通过案例进行了验证分析。     

The linear span of the frequency hopping sequences in optimal sets

Frequency hopping (FH) sequences are needed in FH code division multiple access (CDMA) systems. Recently some new constructions of optimal sets of FH sequences were presented. For the anti-jamming purpose, FH sequences are required to have a large linear span. The objective of this paper is to determine both the linear spans and the minimal polynomials of the FH sequences in these optimal sets. Furthermore, the linear spans of the transformed FH sequences by applying a power permutation are also investigated. If the power is chosen properly, the linear span could be very large compared to the length of the FH sequences.     

Refined Analysis of Sparse MIMO Radar

We analyze a multiple-input multiple-output (MIMO) radar model and provide recovery results for a compressed sensing (CS) approach. In MIMO radar different pulses are emitted by several transmitters and the echoes are recorded at several receiver nodes. Under reasonable assumptions the transformation from emitted pulses to the received echoes can approximately be regarded as linear. For the considered model, and many radar tasks in general, sparsity of targets within the considered angle-range-Doppler domain is a natural assumption. Therefore, it is possible to apply methods from CS in order to reconstruct the parameters of the targets. Assuming Gaussian random pulses the resulting measurement matrix becomes a highly structured random matrix. Our first main result provides an estimate for the well-known restricted isometry property (RIP) ensuring stable and robust recovery. We require more measurements than standard results from CS, like for example those for Gaussian random measurements. Nevertheless, we show that due to the special structure of the considered measurement matrix our RIP result is in fact optimal (up to possibly logarithmic factors). Our further two main results on nonuniform recovery (i.e., for a fixed sparse target scene) reveal how the fine structure of the support set—not only the size—affects the (nonuniform) recovery performance. We show that for certain “balanced” support sets reconstruction with essentially the optimal number of measurements is possible. Indeed, we introduce a parameter measuring the well-behavedness of the support set and resemble standard results from CS for near-optimal parameter choices. We prove recovery results for both perfect recovery of the support set in case of exactly sparse vectors and an \(\ell _2\)-norm approximation result for reconstruction under sparsity defect. Our analysis complements earlier work by Strohmer & Friedlander and deepens the understanding of the considered MIMO radar model. Thereby—and apparently for the first time in CS theory—we prove theoretical results in which the difference between nonuniform and uniform recovery consists of more than just logarithmic factors.     

军事行动避空侦察的时机和路线选择

介绍了军事行动中侦察卫星运动轨迹的预测方法,并规划了最优行军路线.首先根据雷达探测俯仰角与探测距离的几何关系,确定雷达探测经度范围,并对卫星周期及卫星被探测到的初始位置进行求解,从而建立卫星进出雷达探测范围时刻的预测模型,对几种卫星的过顶情况进行预测·最后,在此基础上建立简化的行军路线模型,选择最优行军路线,躲避卫星侦察.     

关于存在多组最优解的整数线性规划问题的割平面法的研究

利用割平面法求解具有多组最优解情形的整数线性规划问题时,会出现不能求出全部最优解的现象,这是割平面法的一个缺陷.针对割平面法的这种缺陷,基于构造非线性标量化函数时引入凸锥的思想,提出了一种割平面一线性交叉搜索方法,这种割平面一线性交叉搜索方法可以解决利用割平面法求解整数线性规划问题时出现的缺陷.最后,通过数值例验证了割平面一线性交叉搜索方法的可行性与有效性.     

Theoretical Complexity of Grid Cover Problems Used in Radar Applications

Modern radars are highly flexible systems, relying on digital antennas to dynamically control the radar beam shape and position through electronic circuits. Radar surveillance is performed by sequential emission of different radar beams. Optimization of radar surveillance requires finding a minimal subset of radar beams, which covers and ensures detection over the surveillance space, among a collection of available radar beams with different shapes and positions, thus minimizing the required scanning time. Optimal radar surveillance can be modelled by grid covering, a specific geometric case of set covering where the universe set is laid out on a grid, representing the radar surveillance space, which must be covered using available subsets, representing the radar beams detection areas. While the set cover problem is generally difficult to solve optimally, certain geometric cases can be optimized in polynomial time. This paper studies the theoretical complexity of grid cover problems used for modelling radar surveillance, proving that unidimensional grids can be covered by strongly polynomial algorithms based on dynamic programming, whereas optimal covering of bidimensional grids is generally non-deterministic polynomially hard.