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较详细地介绍了红外辐射计式、微波多普勒和激光多普勒风切变探测,告警系统的研制发展现状及存在的问题,通过研究给出了一些结论:(1)红外辐射、微波和激光多普勒雷达系统可以用来探测低空风切变,并提供告警时间;(2)红外辐射系统可测量垂直风风速,而微波,激光多普勒协达系统可测量水平风风速,但不论那一种探测系统都无法同时测量水平风和垂直风风速;(3)地杂波是造成微波系统误警的主要因素之一;(4)激波系统对降 相似文献
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通过对高楼(100多米)楼顶微波塔,采用相似原理及环境模拟的方法对微波塔的缩比模型,进行了风洞实验研究,测量微波塔在不同风速及风向角下的气动力特性。研究分析得到楼顶微波塔塔基连接部的受力参数等,为微波塔工程设计应用提供可靠的依据。 相似文献
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在中国空气动力研究与发展中心超高速所弹道靶上利用电子密度测量系统进行了高超声速钢球模型、铜球模型尾迹电子密度测量。电子密度测量系统由8mm微波干涉仪系统、开式微波谐振腔测量系统和闭式微波谐振腔测量系统组成。钢球模型直径φ10mm,速度分别为5.8、5.5、5.6和5.5km/s,对应的飞行环境压力分别为2.79、5.32、5.85和10.91kPa。铜球模型直径φ10mm,速度分别为5.6、5.6、5.7和5.5km/s,对应的飞行环境压力分别为1.33、4.79、5.89和10.91kPa。结果表明:(1)在压力5.3~11kPa范围内、速度约5.5km/s试验条件下,压力越高,钢球模型的尾迹电子密度相应增大,电子密度的衰减速度较快;(2)在压力1.3~6kPa范围内、速度约5.6km/s试验条件下,压力越高,铜球模型的尾迹电子密度相应增大,电子密度的衰减速度较慢;(3)在压力约10.7kPa、速度5.5km/s试验条件下,铜球模型的尾迹电子密度衰减速度比钢球模型慢得多。 相似文献
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在雷达系统中,常以微波作为雷达信号传输的载体,微波传输有很多优点,但是当设备趋于老化时,往往会在雨天、雾天,由于衰减过大而城微波线路暂时中断,使雷达信号不能连续传输,本文针对这个问题提出了一种微波传输系统的应急替代方法--有线传输。 相似文献
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张弘 《中国民航学院学报》2007,25(6):23-26
典型的无线通信系统RF电路由大量的线性和非线性元器件组成。建立这些微波电路元器件的模型在现代RF电路的设计中至关重要。采用一种神经网络来学习非线性电路的动态特性,并建立相应的模型。神经网络模型可以对原始电路的模拟特性进行整体预测,可用于高层电路的仿真和优化。以功率放大器为例验证了神经网络模型的实用性,表明神经网络模型可以极大地提高无线通信系统RF电路的建模精度和速度。 相似文献
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为了探究微波推力器的推力性能,采用三丝扭摆推力测量方法对微波推力器独立系统开展推力测量实验,同时分析三丝扭摆推力测量装置的数理模型并实验测定其不确定度,由此判断实验测量结果的可信度。推力测量结果表明,现有实验条件下三丝扭摆推力测量装置能测出不低于3mN的推力,其相对不确定度为14%;在三丝扭摆推力测量装置的推力测量范围内,没有测出微波推力器独立系统显著的推力,而是在230W微波功率输出条件下测出推力在±0.7mN范围内波动,相对不确定度大于80%。 相似文献
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本文以沈阳桃仙机场为例,从仅表着陆系统的场地和电磁环境两方面讨论了起飞航班对仅表着陆系统信号的影响,并提出了相应的解决建议。 相似文献
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飞机着陆系统的现状与发展 总被引:5,自引:1,他引:4
论述了仪表着陆系统(ILS)、微波着陆系统(MLS)的作用及应用前景和主要优缺点。提出在未来MLS系统逐步取代ILS系统的过程中,ILS/MLS组合着陆系统导航设备的应用与发展。 相似文献
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A typical approach and landing operation is described. The microwave landing system (MLS) is then examined, its design characteristics and how it works are shown, and how the MLS design fulfils the user's operational requirements by protecting the guidance signal from reflected signal interference is highlighted. MLS angle system accuracy is discussed in great detail, and its reliability, integrity, and coverage volume are briefly considered. MLS availability at any runway to all aircraft types and their landing scenarios, which is accomplished using narrow scanning beam antennas, is examined 相似文献
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维护计算机是微波着陆系统(MIS)地面设备的重要附属设备。针对微波着陆系统地面设备维护计算机的具体需求,详细分析了微波着陆系统地面设备维护计算机与相关台站的信息交互关系,介绍了维护计算机软件模块组成、通信协议、实现流程及实现的主要关键技术。该软件已成功运行于某微波着陆系统中。 相似文献
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本文在对民航几个具有代表性的机场和航空公司进行调研基础上,提出了ILS/MLS成本计算和未来机队预测方法,从我国目前应用ILS现状出发,列举了由MLS可能获得的效益。根据成本计算结果的比较和分析,提出了我国ILS/MLS过渡方案参考的结论和建议,供领导机关作决策选择。 相似文献
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Microwave Landing System Area Navigation 总被引:1,自引:0,他引:1
The International Civil Aviation Organization (ICAO) Standards and Recommended Practices (SARPS) states that the Time Reference Scanning Beam (TRSB) Microwave Landing System will supplant the existing Instrument Landing System (ILS) as the recognized international standard as early as 1995. The MLS provides the ability to determine the aircraft's position in three dimensional space over a large coverage volume in the airport terminal area. This affords the capability to navigate and execute approaches throughout this volume of coverage. This technique is known as Microwave Landing System Area Navigation (MLS RNAV). In order to assess and further develop the potential capabilities of MLS RNAV, the FAA Technical Center has undertaken the tasks of performing analytical studies, as well as the development of a prototype MLS RNAV system. 相似文献
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The author describes the MLS installation on runway 19L at Mid-Continent Airport, Wichita, Kansas, which has been operational since mid-1987. He describes the MLS equipment installation in his aircraft, which is one of a number of aircraft in the Wichita area that have been equipped with MLS equipment and routinely utilize the system. He summarizes his operational experience with the system. He reports complete satisfaction and increased versatility as a result of the guidance information provided 相似文献
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The microwave landing system (MLS), which is scheduled to be implemented progressively over the next 10 years, is intended to supply the instrument landing system (ILS) as the international standard landing aid. MLS has been demonstrated to be superior to ILS from both performance and reliability standpoints, yet considerable debate persists on its relative merits. Although tolerance criteria for flight safety are embedded in these comparisons, flight safety has not been a major component of these discussions. The reasons why flight safety has not been an issue are addressed, and observations on the flight safety of MLS are related from a systems point of view. The effect of MLS on airport capacity is identified as a central issue. Observations are derived from a review of available documentation and operational results to date as well as discussions with the participants 相似文献
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The National Microwave Landing Systems (MLS) program is a joint DOT/DOD/NASA effort to implement a common civil/military precision landing system to replace the current Instrument Landing System (ILS). The MLS will be capable of providing precision landing guidance down to Category III minimum while allowing for complex approach paths in both the horizontal and vertical planes. The system is based on the Time Reference Scanning Beam (TRSB) technique which was selected by the International Civil Aviation Organization (ICAO) in April 1978 as the new international landing system standard. MLS is less susceptible to interference from the surrounding area and provides a greater signal coverage area than ILS. 相似文献
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为了配合即将使用的微波着陆系统 MLS,飞行管理计算机必须扩增其区域导航 RNAV 的功能。本文采用平面汇交法和角锥汇交法及其组合,针对方位台,仰角台、测距台非共点发射的一般情况,编制了适应多种情况的MLS RNAV 通用软件,并进行了试算。为今后编制飞机上使用的实时运行软件做好准备。 相似文献
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Instrument approach designs and flight-test results using the microwave landing system (MLS) are presented. A general-aviation aircraft was flown on linear computed centerline and curved approach paths with MLS guidance displayed on basic course-deviation indicator and horizontal situation indicator instruments. Approach performance was documented using a ground tracker system, recording three-dimensional position information. These tests demonstrated the flyability of such advanced paths with basic cockpit instrumentation 相似文献