反潜巡逻机浮标布阵应召搜潜效能研究

搜潜效能是评判浮标阵型优劣的重要依据。本文基于应召搜潜,根据已知的潜艇信息,以反潜巡逻机为平台,建立了不同阵型声纳浮标搜潜数学模型。并运用Monte Carlo方法仿真分析了相同条件下,潜艇初始位置分布、初始距离、潜艇航速对浮标阵搜潜效能的影响。结果表明:同等条件下,声纳浮标方形阵搜潜效能最好,其次是圆形阵、三角形阵;三种浮标阵的搜潜效能都随着潜艇初始位置分布、初始距离、潜艇航速的增大而降低。这为指挥员进行浮标布阵提供了有效的辅助决策依据。     

浮标布阵航路规划算法仿真研究

研究固定翼反潜飞机优化航路规划问题,反潜飞机浮标布阵系统作为航空反潜的重要组成部分.由于固定翼反潜飞机因飞行速度以及同时具备搜潜和反潜的能力,针对固定翼飞机在浮标布放飞行速度下转弯半径过大,使规划航路不能在规定的时间内完成布放任务,对声纳浮标也不能及时对某一海域进行搜索而失去最佳的探潜时机,因此采用线性规划算法已无法满足布放实时性的要求.为解决上述问题,将传统蚁群算法运用到直升机布阵航路规划中,并对其进行了改进,运用到固定翼飞机布阵航路规划中,解决了因固定翼飞机最小转弯半径过大而导致布阵不及时、影响搜索效率等问题,最后对算法寻优和收敛情况进行仿真,结果取得了较好的效果为设计提供了参考.     

舰机协同下多基地声纳阵应召搜潜效能研究

针对传统单基地声纳搜潜难以满足反潜作战要求的问题,提出了一种拖曳声纳与反潜直升机布放浮标阵联合起来形成多基地声纳搜潜的方法。结合舰机实际运动特点,建立舰艇运动模型与直升机布放圆形、方形、三角形被动浮标阵模型。采用Monte Carlo方法,对搜潜概率进行仿真,比较多基地与非多基地声纳的搜潜概率,并分析不同的初始条件对搜潜概率的影响。仿真结果表明,多基地声纳搜潜概率高于非多基地声纳,圆形多基地阵搜潜效能相对最佳,三种阵型的搜潜概率随着初始距离、初始位置分布、航速均值的增大而减小,并能针对不同搜潜要求与实际作战条件选择合适的布放半径和被动浮标布放个数。提出的方法适用于一定距离范围内的应召搜潜,对反潜作战具有一定的军事意义。     

多机吊放声纳检查搜潜建模与仿真研究

为了提高吊放声纳检查搜索概率,建立了4架飞机利用吊放声纳的平行、多段和锯齿检查搜潜模型、潜艇运动模型、搜潜概率模型,仿真分析了潜艇初始航向、吊放声纳间距、搜索样式等因素对检查搜索概率的影响.仿真结果表明,潜艇航速、航向角度以及吊放声纳间距的变化对平行、多段和锯齿检查搜索概率影响较大.使用多机进行协同搜潜,可在较短时间内进行大面积搜索,有效提高搜潜效率.因此,在实际航空反潜中,需根据所获得的潜艇运动态势信息合理选择搜潜样式和有关的搜潜战术手段,才能获得较高的搜潜概率.     

以潜制潜的搜索效能分析与仿真

潜艇在未来的联合反潜作战中将担负重要的使命任务,但是由于潜艇搜索作战仿真模型的匮乏,严重影响了作战研究的科学性.建立潜艇对潜搜索效率模型成为以潜制潜作战研究的瓶颈问题.在认真研究潜艇的搜索过程和影响其搜索效率的各种因素的基础上,分两种情况(反潜潜艇发现目标的距离大于目标开始规避反潜潜艇的距离、反潜潜艇发现目标的距离小于等于目标开始规避反潜潜艇的距离)建立了潜艇对潜搜索效率模型.通过对潜艇搜索效能的仿真分析,提高了以潜制潜作战研究的科学性,给出了保证和提高搜索效率的使用方法.     

声纳浮标阵搜潜效能通用仿真模型研究

通过对声纳浮标阵作战机理的详细分析,以蒙特卡洛法为基础建立了声纳浮标阵搜潜效能的通用仿真模型,并给出了仿真实例。该模型适用于对各种作战条件下各种声纳浮标阵搜潜效能的仿真计算。     

舰载直升机对潜防御性应召搜索仿真分析

研究潜防搜索优化问题,吊放声纳和声纳浮标是舰载直升机对潜搜索的主要手段,但在搜索的过程中存在着因搜索面积大导致兵力需求多和如何协同使用才能达到最优搜索效果等问题。针对舰载直升机吊放声纳和声纳浮标在搜潜中的协同,由于水面舰艇在航渡中受到潜艇威胁,提出了一种舰载直升机对潜防御性应召搜索的方法,通过建立潜艇对水面舰艇威胁航向的模型和仿真分析,能够有效缩小舰载直升机应召搜索的范围;同时,建立了舰载直升机吊放声纳搜索及声纳浮标阵列模型,并对舰载直升机使用吊放声纳和声纳浮标协同搜索进行仿真。仿真结果表明,提高了搜索效率,可为吊放声纳和声纳浮标的作战应用提供重要参考。     

基于被动声纳浮标投放法的水下目标跟踪

针对航空反潜中使用空投被动声纳浮标对潜艇进行跟踪的问题,利用双曲线交汇法定位,研究被动浮标对水下目标进行连续跟踪的方法,建立相应数学模型。仿真结果证明了该方法的可行性,得到目标的航速、航向、运动状态变化间隔、声纳浮标位置等因素变化与跟踪所需声纳浮标数量的关系。     

基于潜艇先验航向信息的编队应召搜索研究

应召反潜是水面舰艇编队常用的反潜方式之一，现阶段研究的应召反潜方法多是在已知敌潜艇先验位置信息条件下的对潜搜索方法，而对于某些特定条件下的对潜搜索不具有普适性。在研究水面舰艇编队平行应召反潜的基础上，建立了潜艇初始位置和概略航向已知、航速未知条件下的水面舰艇编队对潜搜索概率基本模型，并进行了仿真评估。通过Matlab仿真，给出了水面舰艇数量、接敌速度、搜索速度和潜艇机动速度等因素对搜索概率的影响关系，为水面舰艇编队反潜作战提供了理论依据和技术支撑。     

应召搜潜中典型情况下潜艇分布概率的计算

针对应召搜潜过程中潜艇分布概率的计算问题,推导了潜艇的初始位置服从正态分布、潜艇航向在二维平面内服从均匀分布、潜艇航速已知或服从已知分布的潜艇分布概率的计算方法,给出了潜艇航速服从均匀分布和瑞利分布等典型情况下,潜艇分布概率的计算公式,并通过蒙特卡罗方法验证了所推导公式的正确性,同时给出了部分时刻潜艇位置联合概率密度和边缘概率密度的计算结果。通过该计算结果可以清楚地看出应召搜潜中潜艇的分布概率随搜潜时间的变化情况,这对于在搜潜过程中制定正确的搜潜策略具有一定的指导意义。     

Performance evaluation of a non-linear error model for underwater range computation utilizing GPS sonobuoys

Deployed from an airborne platform or a surface vessel, arrays of GPS sonobuoys can be used to efficiently track and localize submarines. The range of the target of interest can be monitored with the deployed sonobuoys. However, the accuracy deteriorates when the target is on the detection range of only one sonobuoy. The objective of this research is to improve the range computation of the target of interest by establishing a non-linear error model for range error using adaptive neuro-fuzzy inference systems (ANFIS), which has the capabilities of dealing with data of high level of uncertainty and the advantage of being based on neural computation. Furthermore, the performance of the proposed model is examined with both experimental real field data and contact-level simulation data considering different scenarios for both the array of GPS sonobuoys and the target. The results discuss merits and the limitations of the proposed method.     

通报距离对应召磁异搜潜概率的影响

为了分析应召搜潜过程中通报距离对搜潜概率的影响,推导出了计算潜艇位置分布概率的模型。通过该模型建立了通报距离与应召磁异搜潜概率的关系,并给出了一些典型情况下的计算结果。结果显示：应召磁异搜潜概率随通报距离的增加迅速下降,仅当通报距离较近且潜艇初始分布半径较小、航速较低时,应召磁异搜潜拥有较高的探测概率;从而表明通报距离对应召磁异搜潜概率影响较大,磁异探测不适合对远的通报距离的区域实施搜索     

DOA estimation based on fourth order cumulant beamforming for nonuniform linear array of DIFAR sonobuoys

The Directional Frequency Analysis and Recording (DIFAR) sonobuoy has been widely used in underwater target localization because it can capture more information than the Low Frequency Analysis and Recording (LOFAR) omnidirectional sonobuoy. Recently, array processing for fields of DIFAR sonobuoys has attracted considerable attention in order to enhance the direction of arrival (DOA) estimation performance and accuracy. DIFAR sonobuoys may become irregularly spaced due to the deployment method and the drift experienced once deployed, resulting in a nonuniform array. In this paper, we demonstrate the fourth-order cumulant beamforming (FOC-BF) technique to estimate the DOA for a nonuniform linear array of DIFAR sonobuoys. FOC-BF was compared with the conventional beamforming (CBF) through simulation works. The results show that FOC-BF provides better spatial spectrum with lower sidelobes than CBF. Furthermore, FOC-BF provides superior DOA estimation accuracy over CBF at very low signal to noise ratios (SNR).     

基于最大输出功率的近场阵列定位算法

在近场阵列中,为了降低信源位置变化对阵列性能的影响,基于最大输出功率,根据近场阵列的特点,提出了一种新的低复杂度快速收敛算法。通过搜索最大输出功率,对信号入射方向进行估计。实现麦克风阵列相应调节阵列权矢量,压制干扰,获得最大的信号增益。使得近场阵列如麦克风阵列能够快速适应位置不断变化的入射信号。与MUSIC等现有算法比较,仿真结果表明了该算法的快速定位性质的优越性。     

Phase‐spacing optimization of linear microstrip antenna arrays using simulation‐based surrogate superposition models

A technique for simulation‐driven optimization of the phase excitation tapers and spacings for linear arrays of microstrip patch antennas is presented. Our technique exploits two models of the array under optimization: an analytical model which is based on the array factor, as well as an electromagnetic (EM) simulation‐based surrogate model of the entire array. The former is used to provide initial designs which meet the design requirements imposed on the radiation response. The latter is used for tuning of the array radiation response while controlling the array reflection response as well as for validation of the final design. Furthermore, the simulation‐based surrogate model allows for subsequent evaluation of the array responses in the beam scanning operation at negligible computational costs. The simulation‐based surrogate model is constructed with a superposition of simulated radiation and reflection responses of the array under design with only one radiator active at a time. Low computational cost of the surrogate model is ensured by the EM‐simulation data computed with coarse meshes. Reliability of the model is achieved by means of suitable correction carried out with respect to the high‐fidelity array model. The correction is performed iteratively in the optimization process. Performance, numerical efficiency, and accuracy of the technique is demonstrated with radiation pattern synthesis of linear arrays comprising 32 microstrip patch antennas by phase‐spacing optimization. Properties of the optimal designs in the beam scanning operation are then studied using the superposition models and compared to suitably selected reference designs. The proposed technique is versatile as it also can be applied for simulation‐based optimization of antenna arrays comprising other types of individually fed elements. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:536–547, 2015.     

Microfabrication of pre-aligned fiber bundle couplers using ultraviolet lithography of SU-8

This paper describes the design, microfabrication and testing of a pre-aligned array of fiber couplers using direct UV-lithography of SU-8. The fiber coupler array includes an out-of-plane refractive microlens array and two fiberport collimator arrays. With the optical axis of the pixels parallel to the substrate, each pixel of the microlens array can be pre-aligned with the corresponding pixels of the fiberport collimator array as defined by the lithography mask design. This out-of-plane polymer 3D microlens array is pre-aligned with the fiber collimator arrays with no additional adjustment and assembly required, therefore, it helps to dramatically reduce the running cost and improve the alignment quality and coupling efficiency. In addition, the experimental results for the fiber couplers are also presented and analyzed.