Microwave Landing System

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.     

微波着陆地面设备维护计算机软件系统研究

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。     

飞机着陆时的容错导航

研究了飞机在微波着陆环境中的传感器容错系统。该系统的主要目的是检测辅助导航设备和机载传感器的故障,并在这些传感器可能发生故障时提供可靠的飞机状态估计值。自动导航和控制系统利用这些状态估计控制和引导飞机按预定路线降落。     

飞行管理计算机的ML SRNAV算法及运行结果

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。     

High accuracy navigation and landing system using GPS/IMU systemintegration

In this paper, the accuracy, integrity and continuity of function requirements for automatic landing systems using satellite navigation systems are discussed. Such a landing system is the integrated navigation and landing system (INLS) developed by Deutsche Aerospace (DASA/Ulm, Germany). The system concepts of the INLS are presented. It is shown how an INLS, based on system integration of a satellite navigation system (e.g., GPS) in realtime differential mode with an inertial measurement unit (IMU) in the accuracy class of an attitude and heading reference system (AHRS), can meet the requirements: the results given are mainly devoted to the accuracy issues. Using Kalman filter techniques, an in-flight calibration of the IMU is performed. The advantage of system integration, especially in dynamic flight conditions and during phases of flight with satellite masking, is explained. The accuracy, integrity and continuity of function of the INLS were proven by means of flight tests in a commuter aircraft using a laser tracker as a reference. These flight tests have shown that the short-term accuracy (<60 seconds) of the AHRS used within the INLS has been improved from low cost sensor quality to the accuracy of a high quality laser inertial navigation system (LNIS). With the presented INLS, a landing at any airfield, not equipped with conventional Instrument Landing System (ILS) or Microwave Landing System (MLS), is possible by using a very cost effective system. The INLS is a high accuracy navigation and landing system designed to be used instead of conventional landing systems at small airfields and to fill operational gaps of conventional navigation and landing systems in cruise and approach on large airports     

最小生理噪声进场航迹飞行管理方法

 微波着陆系统MLS的最优航迹计算以减小居民最敏感的生理噪声为基本优化性能准则,用感觉噪声级Sone为单位。计算了考虑了噪声传播时温度、风梯度、沿进场航迹附近区域生活居民区分布位置及密度等影响。通过对杜塞尔道夫-罗奥申航空港计算结果证实,使航空港附近居民的平均有效感觉生理噪声级(Sone)较原有Jeppesen标准方式降低了20％以上。     

Channel Measurement/Modeling for Airport Surface Communications: Mobile and Fixed Platform Results

We provide examples of measurement and modeling results for wireless channel characteristics around airport surface areas. This is done for three settings: two mobile settings and one non-mobile setting, in the 5 GHz Microwave Landing System extension band. New findings, useful for communication system design in this environment, are reported.     

MLS: a total system approach

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     

Portable approach landing system design

This paper presents a design concept for an azimuth and an elevation antenna suitable for the light weight Portable Approach Landing System (PALS). The proposed design complies with the requirements of the International Civil Aviation Organization (ICAO) Annex 10. Based on a proven technology, the proposed design offers a low risk and a cost effective approach     

Design of an image radiation monitor for ILS glide slope

The design of a monitor that measures changes in ground reflected image radiation is presented. This monitor is shown to be theoretically capable of determining the effects of snow cover and standing water in the vicinity of an Instrument Landing System (ILS) image-type glide slope, thereby reducing the number and length of outages. A discussion of errors and calibration are presented, along with an example of a practical design     

Measuring Aircraft Carrier Flexure in Support of Autonomous Aircraft Landings

This paper quantifies the experimental measurements of aircraft carrier flexure (deformation) at sea in support of the United States Department of Defense sea-based Joint Precision Approach and Landing System (JPALS) that aims to deliver automatic landing capabilities to inbound aircraft aboard aircraft carriers. The methodology for measuring ship flexure using the Global Positioning System (GPS) and inertial sensors is described. Results indicate that flexure on the aircraft carrier used for testing has a standard deviation of approximately 1–2 cm. For the ship tested, the most significant flexure effects are in the port/starboard direction and correlate best with roll or lateral acceleration.     

飞机自动进近和自动着陆的分析研究

本文首先概述了当前民航客机的自动导航、进近、着陆的全过程。随着重点分析了波音737飞机利用SP-77自动飞行控制系统与仪表着陆系然的航向信标仪和下滑仪及机载无线电高度表等设备实现向跑道自动进近和自动着陆的工作过程,并系统介绍了在实现上述过程中,SP-77自动飞行控制系统的自动驾驶仪横滚通道和俯仰通道控制逻辑的建立,系统工作电路的转换,系统的控制规律和工作特点。     

基于Gauss平均引数的RNAV进近程序航迹引导参数计算

为准确计算基于WGS-84坐标的RNAV进近程序航路点坐标和航迹引导参数,提供精密RNAV导航数据,降低RNAV进近系统误差,提出了实测跑道入口WGS-84坐标,然后沿跑道中线外推各航路点WGS-84坐标的计算方法。采用Gauss平均引数法对各航段的航线角及航段距离进行了反算,以验证外推航路点坐标的计算精度。通过西南地区某机场＂T＂型RNAV进近程序的设计及飞行验证,该方法可推广到其他机场的RNAV进近程序设计。     

微波着陆信息处理系统研究

微波着陆信息处理系统是MLS机载设备在研制、生产和维修过程中必不可少的一种专用测试设备,文中论述了研究微波着陆信息处理系统的必要性,并从硬件结构上说明了微波着陆信息处理系统的工作原理。     

考虑几何限制的航向道模式设计

民机自动飞行系统在截获LOC信标切入跑道中心线时，由于空间几何限制导致较大超调，会对飞行安全产生不利影响。针对这一问题，设计了一种考虑几何限制的航向道模式。为了解决LOC线性区外信号不能用于自动飞行指令计算的问题，利用飞行管理系统的现有功能计算出飞机偏离跑道中心线的水平偏差；使用切入点位置和最大滚转角的几何限制作为机动判断条件，同时以进入线性区作为LOC模式的激活条件，使得飞机在达到几何限制时能提前机动。最后，通过仿真对比了采用三种不同LOC截获方法时飞机的响应，仿真结果表明所提出的方法能够有效解决因几何限制导致的LOC截获超调问题。     

模型预测控制（MPC）在飞机自动着陆系统中的应用

进场着陆是飞行的复杂阶段,虽然仅占整个飞行的2%～3%,却大约有1/3的飞行事故发生在此阶段,而高速喷气式飞机的飞行事故有一半以上是发生在进场着陆阶段。本次仿真的对象是一种具有特殊外形的无人机,对侧向着陆精度要求很高。于是文中采取了预测控制器加经典PID控制器构成了分层控制系统。动态矩阵法的在线优化和反馈校正等特点有效地提高了系统的整体性能。结果表明,这种方法可以有效地提高着陆精度并严格控制接地时的滚转角。     

A blackboard architecture of the microwave generic controller forthe DSN antenna subsystem

This paper presents a Hayes-Roth blackboard architecture for the Microwave Generic Controller (UGC) for the Antenna Microwave Subsystem in the NASA Deep Space Network. A formal specification of the current UGC and the new blackboard architecture is also given using the Higher-Order Logic (HOL) Proof System. HOL makes it possible to provide a straightforward, unambiguous and consistent specification of the UGC. The UGC is responsible for monitoring and controlling the switches and rain blowers for the Antenna Microwave Subsystem. The new blackboard architecture for the UGC introduces a collection of parallel processes called knowledge sources. Because of the parallel nature of the blackboard and the ability to retrieve the most current information quickly, there is a gain in efficiency. In addition, the blackboard architecture of the UGC is extensible, which is in keeping with the design philosophy of the UGC     

仪表着陆系统设备混合监控网络构建

针对传统仪表着陆系统设备"点-点"遥控监控方式易中断,影响运行安全这一问题,提出了一种基于光纤与线缆的"多点-环网"混合监控方案。光纤与线缆互为补充,互为备份,并且当某路监控链路故障时,可自动选择其它监控路径,有效提高仪表着陆系统设备监控效率,增加监控冗余度,为我国民用机场导航监控提供一种新思路。该方案已经成功在重庆江北机场运行。     

Some early achievements in landing guidance using mechanicallyscanned pulse-encoded beams

A microwave scanning beam landing system from the 1950s and 1960s is still operating routinely. It depends on airborne reception of pulse-coded signals from mechanically scanned antennas. Military versions include the US Navy's C-Scan for carrier landings and the Tactical Instrument Landing System used in Sweden. Other sets, called microwave scanning beam landing systems, serve Space Shuttle orbiters. System concepts and functional hardware requirements were tested extensively by on-ground and flight procedures. Both the US Navy and Sweden purchased operational equipments in 1969     

The BOOMERANG experiment

The BOOMERANG (Balloon Observations Of Millimetric Extragalactic RAdiation aNd Geophysics) experiment is an international effort to measure the Cosmic Microwave Background (CMB) anisotropy on angular scales of 20 to 4°, with unprecedented sensitivity, sky and spectral coverage. The telescope will be flown from Antarctica by NASA-NSBF with a long duration stratospheric balloon (7–14 days), and is presently scheduled for flight in 1995–1996. The experiment is designed to produce an image of the Cosmic Microwave Background with high sensitivity and large sky coverage. These data will tightly constrain the baryon density, the reionization history, and the formation of large-scale structure in the universe. BOOMERANG will test technologies and return science data that are essential to the design of a future space-borne mission to map CMB anisotropy.