弓网电弧辐射特性及对机场下滑信标的影响

为获得弓网电弧辐射特性及从理论上分析其对机场下滑信标的影响。选择典型电气化动车线路,首先基于CISPR16-1标准,利用电磁干扰接收机对电分相和普通点处的弓网电弧电磁辐射进行点频测试,获得了其在下滑信标台频谱内的辐射特性,然后基于电波传播理论,以电气化轨道平行跑道为例,分析了弓网电弧电磁辐射对飞机导航的影响。结果表明：电弧电磁辐射具有一定的随机特性,普通点处产生的电磁辐射场强小于电分相处;普通点的电磁辐射不会对飞机的导航产生干扰;当轨道距跑道中心的距离分别为700、120和60 m时,电分相拉弧点距下滑信标台天线的距离应分别小于3 291、546和249 m时才不会对飞机的导航产生干扰。本结果能够为轨道电气化和民用航空这两大工业体系在机场区域的电磁兼容性设计提供依据。     

DVOR常见故障产生原因及排除方法

一、VOR简介 甚高频全向信标（VOR）是现代航空无线电测向导航的一种地面设备。目前国际上存在两种不同制式的甚高频全向信标，一种是普通全向信标（CONVENTIONAL VOR，CVOR），另一种是多普勒全向信标（DOPPLER VOR，DVOR），两种全向信标对机载VOR接收机而言是兼容的。     

某全向信标飞行校验中弯曲超限分析

详细分析了全向信标/测距仪(VOR/DME)的飞行校验原理及在飞行校验过程中的一些重要参数,明确这些参数在飞行校验系统中的计算方法。以一次全向信标/测距仪实际飞行校验过程中遇到的"弯曲"参数超限为例,分析了参数超限的原因,并将设备参数调整到标准范围内,为相关人员提供一些技术参考,提高飞行校验效率,有助于机场节约成本。     

高铁弓网电弧对飞机进近着陆的电磁干扰影响

为了研究高铁弓网离线电弧对飞机进近着陆的电磁干扰（EMI）影响,选取高速铁路弓网离线现象发生频繁的电分相处,对高速铁路列车发生弓网离线电弧时的电磁辐射强度进行了实际测试。根据电波传播理论和GB 6364-2013的相关要求,数值计算得到了高铁下穿角、电分相位置以及飞机着陆高度对机载接收信号的影响规律：机载接收信号信干比（SIR）随着高铁下穿角增大逐渐增大;电分相距离机场跑道口越近机载接收信号的信干比越小;随着飞机进近着陆高度的减小,机载接收信号信干比先减小后增大。以高速铁路45°角下穿机场跑道中心时,以飞机受干扰最强的位置分析了弓网离线电弧电磁干扰对仪表着陆系统（ILS）信标台的影响：飞机接收到的航向信标台信号信干比为12.92 dB,小于GB 6364-2013规定最小20 dB的防护率要求;下滑信标台信号信干比为29.08 dB,符合国标要求;指点信标台信号信干比为16.64 dB,小于国标规定的最低23 dB的防护率要求。本文研究为民航与高速铁路的电磁兼容性研究提供了理论依据和技术方法,可以为机场选址和高速铁路选线规划提供支持。     

基于ADS的ATC系统

一、引言空中交通管制(ATC)以通信、导航和监视(CNS)为基础。在本国和局部地区,一般利用甚高频(VHF)无线电进行通信,主要通过甚高频全向信标和测距仪(VOR/DME)进行导航,通过雷达/信标系统进行监视。由于这些CNS系统的覆盖范围受到航空器和地面站之间视距传输的限制,因此,VHF、VOR/DME和雷达不能用于海洋和边远地区。     

论全向信标和测距仪的信号覆盖

从甚高频全向信标(VOR)和测距仪(DME)的信号传播原理和作用半径入手,结合机载无线电导航系统的工作特性及现有地面设备的布局,举例分析了华东地区两条主要航路的信号覆盖;并针对实际存在的问题,论述了如何以较小的代价来达到更完善的信号覆盖.     

陆基区域导航实际导航性能评估方法研究

甚高频全向信标(VOR)系统和测距仪(DME)系统是目前最常用的无线电导航系统,而VOR/DME导航和DME/DME导航更是区域导航(RNAV)系统推荐的方式。为满足区域导航所需导航性能要求,对区域导航系统的实际导航性能评估成为关键。在对无线电测量误差分析的基础上,对VOR/DME和DME/DME两种导航方式的实际导航性能评估方法进行了研究,并采用数字仿真对提出的方法进行验证。试验结果表明,提出的实际导航性能评估方法正确,能够有效跟踪实际导航误差,对于后续无线电区域导航技术在机载航空电子设备上的应用具有重要的参考价值。     

基于MC145152的VOR地面信标模仿仪频率合成器的设计与实现

本文提出了VOR地面信标模仿仪对频率合成器的要求,介绍了集成锁相环芯片MC145152的工作特性,验证了基于MC145152的PLL频率合成器在VOR地面信标模仿仪中的设计与实现的有效性。     

基于MC145152的VOR地面信标模仿仪频率合成器的设计与实现

提出了VOR地面信标模仿仪对频率合成器的要求,介绍了集成锁相环芯片MC145152的工作特性,验证了基于MC145152的PLL频率合成器在VOR地面信标模仿仪中的设计与实现的有效性。测试结果证明设计的合理性与实用性,系统频率稳定度优于10-7。     

调频广播对飞机ILS,VOR和VHF通讯干扰的研究（一）

本文介绍了联邦通讯委员会与联邦航空管理局密切合作，消除调频广播电台对飞机仪表着陆系统，甚高频全向信标和甚高频通讯系统的干扰问题，改进并力求解决调频广播电台对普通航空收音机仪表着陆系统的干扰。     

Development of 1000-mHz Distance Measuring Equipment

The major radio aids to air navigation are listed. Underlined are those whose signal format is standardized by the International Civil Aviation Organization (ICAO) and they have now all been the subject of the IEEE Aerospace and Electronic Systems Society Pioneer Award, as follows: airborne direction finder/nondirectional beacon (ADF/NDB), Busignies and Moseley, 1959; VHF omnidirectional range (VOR), Stuart, 1962; instrument landing system (ILS), Kramar 1964, Alford 1965; air traffic control radar beacon system (ATCRBS), Williams, Bowden, and Harris, 1973; distance measuring equipment (DME), Dodington, 1980. A brief history of the development of the distance measuring equipment, which also formed the basis for an IEEE National Aerospace Electronics Conference luncheon address, is given.     

甚高频全向信标改造成数字通信测向综合化系统的几种新方案

受卫星导航的冲击，甚高频全向信标（VOR）在未来航行系统中将失去它的重要地位，最终可能关闭。为充分利用VOR的频段和设备资源，本文提出了四种VOR发射机改造方案：第一是间断发射的慢速时空调制系统；第二是连续发射的二进制四相时空调制系统；第三是码分有参考信号时空调制系统；第四是时分有参考信号时空调制系统。给出了四种系统信号调制、编码、接收机设计等解决方案。改造系统的主要优点是将数字通信和无线定向综合为一体。     

On the Perfomance of Air Traffic Control Radar Beacon System

The sidelobe suppression and improved sidelobe suppression mode performance of terminal and enroute air traffic control radar beacon systems using the existing antenna and a typical improved antenna in the presence of perfectly dielectric flat ground are investigated theoretically. Necessary analytical expressions for various quantities characterizing the system performance have been derived. A general purpose computer program has been developed for the computation and tabulation of these quantities as functions of the elevation angle of the observation point and for different combinations of heights of the directional and omnidirectional antennas of the beacon. Although the discussions given here apply to some specific antenna configurations, the theoretical method developed has more general application in evaluating quantitatively the performance of the beacon system in a given situation.     

Wide-Aperture Digital VOR

The very high frequency (VHF) omnirange has undergone a number of evolutionary changes in the past 30 years. Early measurements of large errors led to the development of the Doppler VHF omnidirectional irectioal range (VOR) and its use. Further developments have been the precision multilobe VOR and the precision Doppler VOR. Interest in area navigation has led to the desire for a VOR greatly superior to any so far developed. Specifically, the objectives of the improved VOR would be a system that would significantly reduce magnitude of siting errors, provide greater accuracy and use digital techniques to simplify processing. ssing. The wide-aperture digital VOR described herein has been developed to meet these objectives. Its design is based on the crossed-pair interferometer principle where eight such pairs are energized successively by a set of pulses and phase shifts. The time multiplexed signal, detected by the aircraft receiver, is processed and simple digital computations are performedto determine the angular coordinates. The performance improvements have been achieved by the combination of using a 275-ft antenna aperture, and the use of digital techniques to generate the ground-radiated navigational signals and to process them in the airborne processor. Field tests of the feasibility model indicate it is a high performance ance system, capable of achieving an order of magnitude improvement in both site error reduction and in accuracy compared to present VOR systems. The measured accuracies were 0.11-degree standard deviation.     

An Inverted VOR of Small Aperture

A new type of omnirange very-high-frequency omnidirectional radio (VOR), intended to be compatible with existing receivers, is described. It is ``inverted' in the sense that reference phase is transmitted by AM, as in the Doppler VOR (DVOR). Variable phase is radiated as a rotating square-wave FM field, the radiating elements being concentric loop antennas with circumferences equal to integer numbers of wave-lengths. Each loop radiates one term in the Fourier expansion of the variable phase field.     

先进战斗机对机载射频孔径系统隐身的需求及解决方案

 大量的研究结果已经表明：机载天线等传感器孔径的分布与形状特征,对飞机隐身效果具有举足轻重的影响,如果不能有效控制机载射频(RF)孔径系统的特征信号(包括雷达散射截面(RCS)和电磁辐射控制),则通过外形、结构和材料隐身而达到的整机高隐身水平就会受到破坏。迄今为止,天线散射特性的评估是尚未完全解决的问题,而减缩天线RCS的手段和方法也有待深入研究。总结了F/A-22和F-35等国外先进隐身战斗机机载射频孔径系统隐身设计特点,从飞机总体隐身方案设计角度提出了对机载射频孔径系统隐身的需求,并针对具体应用提出最小化天线孔径数量、减小天线孔径外形尺寸、减缩天线孔径特征信号、采用低截获概率（LPI）技术等概念性解决方案。     

Preliminary Evaluation of GPS Performance for Low-Cost General Aviation

Preliminary results of a simulation effort to evaluate the requirements and feasibility of the global positioning system (GPS) as a civil air navigation system are presented. Evaluation is made of GPS requirements, from operational considerations, such as application to nonprecision approaches. The conceptual low-cost GPS receiver simulated here does not correct for the ionospheric or trophospheric delay, is sequential in nature, tracks only four satellites, and is not mechanized to make independent range rate measurements based on the Doppler shift of the GPS carrier frequency. The proposed GPS system has significantly different performance characteristics from the presently used VHF omnidirectional range (VOR) solidus distance-measuring equipment (DME) system. The GPS is a low signal level system and many have a relatively slow data rate due to the low-cost sequential receiver design. The results indicate that although the conceptual low-cost GPS receiver/ navigator is potentially more accurate than a VOR, the accuracy may degrade during aircraft turns and satellite shielding periods.     

有理双圆弧插值与双圆弧样条曲面

阐明了用有理参数形式表示圆弧的充要条件。在此基础上建立了由三点确定的双圆弧的有理参数方程。提出了有理双圆弧插值的算法,其中包括建立连续性方程,计算弦切角以及构造样条曲线。此外,构造了一类以双圆弧样条为横向截线的直纹曲面