一种GPS载波相位差分相对定位算法

导航定位技术是空间卫星交会对接任务的关键技术。导航定位精度要求达到厘米级,工程实现难度大。为了解决该问题,本文基于卫星交会对接任务需求,提出采用GPS载波相位差分相对定位算法对卫星进行高精度导航定位。该算法利用测量之间的强相关性,通过误差消除获得高测量精度。同时,本文应用该算法结合星载GPS天线进行了外场试验验证。试验结果表明,GPS载波相位差分相对定位算法精度达到厘米级,可以满足卫星交会对接任务的导航定位测量要求。     

对雷达导引头的极化域电磁干扰机理与仿真

防空、反舰、空对空、空对地导弹普遍采用单脉冲雷达主动寻的制导方式,这种雷达精确制导武器严重威胁了机载平台、大型舰船以及地面等重要军事目标的安全。为了对抗这种威胁,将电子攻击和硬杀伤武器进行组合无疑是上策,但在升空平台和舰艇上对单脉冲跟踪制导雷达进行电子电磁干扰存在很多技术困难。针对这个问题,研究了极化域电磁干扰的可行性,分析了其极化域电磁干扰机理、干扰条件和干扰方法,得到了目标回波和极化干扰共同作用下的定向误差曲线。仿真实验结果表明:天线系统的几何形状以及反射面和辐射器不够完善、辐射器偏离反射器的焦点和绕射现象等,引起了交叉极化,天线罩对入射波的不均匀插入相位延迟和传输系数,增大了交叉极化水平,使得雷达精确制导武器易受极化域电磁干扰的影响,且干扰角误差可达到波束宽度的量级。交叉极化干扰技术亟须从理论研究进入实际装备阶段,应引起工业部门的高度重视。     

无人机机载光学传感器

近年来,光学传感器取得了长足的发展,被用于侦察监视、警戒、观察瞄准和精密制导等各个领域,是现代军事装备中不可或缺的组成部分。其中作为精密制导武器应用的有:图像制导型红外导弹、战车等观察瞄准用的夜视装置、飞机上安装的夜间安全导航用的前视红外装置(FLIR)、飞机和舰船上安装的用于弥补火控雷达缺陷的被动式目标红外搜索与跟踪装置(IRST)。而其他用途包括监视侦察任务,如所谓的图像情报(IMINT)和信号情报(SIGNT)。在监视侦察传感器中,最具有代表性的是侦察卫星,此外就是问世不久的无人机。在美国国防高级计划局构想中,无人…     

GPS接收机超宽带电磁脉冲效应

GPS是现代高技术武器的眼睛之一,它能够为全球任意地点、任意多个用户同时提供高精度、全天候、连续、实时的三维定位、测速和时间基准,可以满足军事部门对海上、陆地和空中运载体进行高精度导航和定位的要求。GPS已经大量用于导弹制导和军用飞机导航,使用GPS或GPS／INS联合制导已经成为导弹制导的最好选择之一。然而,GPS的导航、定位和授时功能都是通过GPS接收机来完成的,如果GPS接收机不能正常的工作,GPS将失去它应有的作用。     

二元光学在光学观测轰炸瞄准中的应用研究

光学观测瞄准是大中型轰炸机主要的对地攻击瞄准方式,其光学系统一般采用望远式光学系统,这就要求光学系统能满足可见光和近红外光两个光谱波段。根据国内大中型轰炸机光学观测瞄准系统的主要缺陷,结合光学观测瞄准的实际,探讨了基于二元光学的光学观测系统的组成结构和瞄准原理,分析了可见光波段混合目镜的光学性能、谐衍射物镜的衍射效率以及近红外光波段光学系统的像质,推导了横偏棱镜调平误差引起的瞄准误差的数学表达式,并对设计的合理性进行了验证。     

光学制导技术(续一)

<正> 一、概述1.引言光学寻的制导也称光学导引,是用制导武器上的设备接收目标辐射或反射的光波(包括天然和人为的可见光、红外辐射)形成点源信号或图像信号,经过处理后实现对目标的跟踪和对制导武器的控制,使制导武器飞向目标的一种技术。因此光学寻的制导技术可分为光学点源信号寻的制导和光学图像寻的制导两大类。光学点源信号寻的制导中红外点源制导和     

精确制导武器

 制导武器是指被人们通过某种技术措施而导引和控制的武器。精确制导武器是采用高精度制导系统,直接命中概率很高的导弹、制导炮弹和制导炸弹等武器的总称。     

目标测偏统计用于对成像制导的激光干扰效果分析

对成像制导武器的激光干扰是一个复杂的过程,当干扰源或干扰对象的参数以及两者之间的相对关系发生变化时,都会对干扰效果产生影响。提出了一种基于目标图像测量统计的干扰效果评估方法,对CCD成像探测系统的激光干扰进行了仿真试验,结果表明目标测偏量的均差和方差能够直接反映CCD成像跟踪系统在激光干扰下的受干扰程度,是对成像制导的激光干扰效果分析的一种有效途径。     

基于变结构理论的中制导律设计方法研究

对于采用复合制导的空地导弹,中末制导交接班问题是影响命中概率的关键因素。针对这一问题,采用变结构理论设计中制导律。首先建立滑模面,保证滑模面上速度矢量与视线重合,且零化视线角速率,然后设计到达函数,使到达条件得到满足,可以保证交班时刻导弹可靠捕获目标,并为末制导提供最优初始条件。建立了导弹六自由度数学模型和目标捕获模型,进行全系统数字仿真,实验结果表明：在中末制导交接时刻,弹目视线与导弹速度矢量基本重合,误差为0.12°,视线角速度为-0.02°/s,在±20°视场下满足捕获需求,并且为末制导提供最优初始条件。该方法可以满足中末制导交接班要求,具有较强鲁棒性,且中制导段弹道平滑,需用过载小。     

基于MEMS惯性器件的行人室内定位系统

基于惯性传感器的行人航位推算系统不需要预先安装任何基础设备,能自主运行、实现实时行人定位。设计的硬件平台将低成本、低功耗、小尺寸的MEMS惯性传感器与GPS接收机相结合。在室内、城市峡谷等GPS信号不稳定的环境,惯性传感器根据前一GPS定点推算行人行走的相对位置。行人所处位置高度由气压计测量,与平面位置相结合实现三维定位。简单而有效的跨步探测及步长估计算法降低对微处理器的计算及存储要求。利用互补滤波器融合加速度计、陀螺仪、数字罗盘数据,降低方位误差、提高定位精度。室内行人行走测试实验表明:定位误差低于总行走距离的3%。验证了系统的准确性和可靠性,满足行人定位要求。     

Optimal guidance law design for impact with terminal angle of attack constraint

According to the requirements of the precision guidance of air-to-surface weapons with multiple constraints, a new optimal guidance law applying to attack the ground stationary target is designed. On the basis of dividing the 3D movement of the weapon into the movements of diving plane and turning plane, the relative motion of weapon-target is established first. Considering the conditions of miss distance, impact angle and terminal angle of attack, the general formulation of a new guidance law with an arbitrary system order is deduced by solving the Riccati equation of the quadratic optimal control. The approximate expressions of lag free system and first-order lag system are given. The validity of the optimal guidance law is verified by the comparable simulations of the characteristic trajectory. The simulation results shows that the optimal guidance laws satisfy the precision guidance with impact angle constraint as well as the angle of attack converges to zero at final time, which is important for warhead effect.     

A simplex method for the orbit determination of maneuvering satellites

A simplex method of orbit determination (SMOD) is presented to solve the problem of orbit determination for maneuvering satellites subject to small and continuous thrust. The objective function is established as the sum of the nth powers of the observation errors based on global positioning satellite (GPS) data. The convergence behavior of the proposed method is analyzed using a range of initial orbital parameter errors and n values to ensure the rapid and accurate convergence of the SMOD. For an uncontrolled satellite, the orbit obtained by the SMOD provides a position error compared with GPS data that is commensurate with that obtained by the least squares technique. For low Earth orbit satellite control, the precision of the acceleration produced by a small pulse thrust is less than 0.1% compared with the calibrated value. The orbit obtained by the SMOD is also compared with weak GPS data for a geostationary Earth orbit satellite over several days. The results show that the position accuracy is within 12.0 m. The working efficiency of the electric propulsion is about 67% compared with the designed value. The analyses provide the guidance for subsequent satellite control. The method is suitable for orbit determination of maneuvering satellites subject to small and continuous thrust.     

光纤制导双向传输系统

光纤制导战术导弹是一种精确制导武器,它主要用于远距离打击敌方的高价值目标,光纤制导战术导弹具有射程远,抗电磁干扰,隐蔽发射,图像制导等一系列优点,因而受到军方的高度重视并得到迅速的发展,光纤双向传输系统是光纤制导导弹系统中一个重要标志性的组成部分。本文详细地介绍弛光纤制导双向传输系统的特点,构成及工作原理。     

新型反坦克武器精确制导体制分析

本文概述精确制导反坦克武器的发展现状及其制导特点，分析未来新型制导兵器应重点发展的几种先进的制导方式，提出精确制导应走多功能化、多制导类型兼容发展道路的建议。     

Applications of two-way satellite time and frequency transfer in the BeiDou navigation satellite system

A two-way satellite time and frequency transfer(TWSTFT) device equipped in the BeiDou navigation satellite system(BDS)can calculate clock error between satellite and ground master clock. TWSTFT is a real-time method with high accuracy because most system errors such as orbital error, station position error, and tropospheric and ionospheric delay error can be eliminated by calculating the two-way pseudorange difference. Another method, the multi-satellite precision orbit determination(MPOD)method, can be applied to estimate satellite clock errors. By comparison with MPOD clock estimations, this paper discusses the applications of the BDS TWSTFT clock observations in satellite clock measurement, satellite clock prediction, navigation system time monitor, and satellite clock performance assessment in orbit. The results show that with TWSTFT clock observations, the accuracy of satellite clock prediction is higher than MPOD. Five continuous weeks of comparisons with three international GNSS Service(IGS) analysis centers(ACs) show that the reference time difference between BeiDou time(BDT) and golbal positoning system(GPS) time(GPST) realized IGS ACs is in the tens of nanoseconds. Applying the TWSTFT clock error observations may obtain more accurate satellite clock performance evaluation in the 104 s interval because the accuracy of the MPOD clock estimation is not sufficiently high. By comparing the BDS and GPS satellite clock performance, we found that the BDS clock stability at the 103 s interval is approximately 10.12, which is similar to the GPS IIR.     

An analysis of the wide area differential method of geostationary orbit satellites

This work aims to obtain a wide area differential method for geostationary orbit (GEO) constellation. A comparison between the dilution of precision (DOP) of four-dimensional (4D) calculation including satellite clock errors and ephemeris errors and that of three-dimensional (3D) calculation only including ephemeris errors with the inverse positioning theory of GPS shows the conclusion that all the 3D PDOPs are greatly reduced. Based on this, a basic idea of correcting satellite clock errors and ephemeris errors apart is put forward, and moreover, a specific method of separation is proposed. Satellite clock errors are separated in a master station with time synchronization, and all the remaining pseudo-range errors after the satellite clock errors have been deducted are used to work out ephemeris corrections of all GEO satellites. By a comparative analysis of user positioning accuracy before and after differential, the wide area differential method is verified to be quite valid for GEO constellation. Supported by the National Natural Science Foundation of China (Grant No. 10778715), the National Key Basic Research Development Program of China (Grant No. 2007CB815502), and the Scientific Research Fund of Hunan Provincial Education Department (Grant No. 08B039)     

导引头性能可视化数据获取方法

目前,制导武器系统导引性能评估主要采用室内仿真和实弹射击方法。但是,受模拟条件的限制,室内仿真存在目标瞬变作用机理描述不足及过程复现可信度低等难题;而外场实弹射击则存在试验样本量有限,目标环境设定单一且射击条件无法保证一致性的问题,难以全面考核出武器系统对环境和干扰的适应性。针对这一问题,提出了一种介于室内仿真与外场实弹试验之间的中间验证考核方法,在接近真实复杂战场环境条件下,构建了制导武器系统的可视化动态测试平台,获取导引头探测、识别和跟踪目标过程的同步、实时可视化观瞄图像,提取目标信息并实现导引性能评估。这种方法在靶场环境下针对实际靶标目标进行静态、动态跟踪试验,能够为激光、毫米波、电视以及红外等不同制导模式的导引头系统进行集成试验与测试,可为室内仿真提供目标背景的直接驱动数据,提升仿真逼真度; 同时,也可多次重复考核导引环节的关键能力,弥补实弹射击试验数量的不足,为武器系统研制过程提供了一种全新的测试验证手段     

基于变焦系统的红外成像目标模拟器研究

随着红外对抗技术的发展,红外成像制导已成为光电精确制导技术的一个发展方向。简要介绍了红外成像制导武器系统半实物仿真的发展现状。针对目前半实物仿真采用一弹一仿的问题,提出了基于五轴转台的新型仿真方案。通过采用变焦距投影系统目标模拟器,使得不同视场、不同焦距、不同型号的导引头可采用同一套仿真系统进行仿真测试,提高了仿真系统的效费比。设计了衍射受限长波红外变焦投影光学系统,系统变倍比为2 3,弥散斑直径小于50μm。     

激光致盲干扰效果评估方法研究

研究了激光致盲干扰设备对光电制导系统、光电成像系统和激光测距机干扰效果的评估方法,分别提出了相应的干扰效果评估准则。对于光电制导系统,可以根据实施激光致盲干扰后制导武器的脱靶量是否超出正常制导精度的三倍或杀伤半径判定干扰是否有效,并根据干扰成功率的大小划分干扰等级。对观瞄用光电成像系统的干扰效果,可以按照致盲激光对成像功能的损伤、破坏程度划分为四个等级;对跟踪用光电成像系统的干扰效果可以根据实施干扰后成像系统能否输出有效跟踪脱靶量,以及脱靶量是否超出正常跟踪精度的三倍判定干扰是否有效。对激光测距机的干扰效果可以依据致盲激光对测距机测距精度、测距能力的影响程度划分为四个等级。