基于多目标优化的运输机任务设备配置研究

为得到合理的任务设备配置比例,对运输机任务设备配置进行优化。军用运输机可执行多种任务类型,需要配置不同的任务设备以实现货舱构型的转换。任务设备的配置比例应兼顾任务成功率、经济性和利用率等多目标要求。为此,以小规模运输机队为研究对象,给出了任务设备配置目标优化原则和边界条件,建立了配置模型,运用线性加权和法进行求解,并进行了模型灵敏度分析和偏差分析,得出了各任务设备的最佳配置比例,可解决小规模运输机队的任务设备配置问题。实例证明了配置结果的有效性。     

一种基于历史标校数据的移相值预测方法

地面测控设备在执行测控任务前,需要对和差接收通道的相位差进行标校(简称校相),以满足测角分系统的目标自跟踪要求.针对因标校设备故障而无法进行校相的问题,通过使用数理统计的多元回归分析方法,对积累的历史标校数据进行分析,确定了设备工作的环境温度对跟踪接收机移相值有显著影响.在此基础上,利用滑动窗口多项式拟合方法得到拟合移相值,并与最近一次的标校移相值进行时变加权,可以得到基于历史标校数据的移相值预测方法.仿真试验表明该方法具有较好的预测精度,可将预测移相值作为跟踪接收机参数,提高测控设备应急测控能力.     

The Economic Analysis of Maintainability

The economic analysis of maintainability is concerned with the selection of one of several feasible alternative maintenance resource allocations. The available resources are specified by the operational deployment of the prime mission equipment. Operational requirements such as reaction time, on-station time, dispersal time, and mission time will directly affect maintenance doctrine and hardware. The complexity of the cost-operations-maintenance interaction and the consequences of decision are such that the selection of an alternative cannot be done by chance or by the adoption of the first feasible solution. This paper discusses the application of appropriate analytic techniques to the formulation of a cost-effective tactical doctrine.     

Leasecraft: An Innovative Space Vehicle

The Leasecraft system is an innovative means to provide a permanent mobile platform in low Earth orbit and the related launch, integration, test, operation, and in-orbit servicing for payloads of industrial and government users. The Leasecraft system is being funded and developed by Fairchild Industries and furthers the industrialization of space with its significant business potential. The technology and techniques underlying this venture are derived from the shuttle compatible multimission modular spacecraft (presently used for the NASA solar maximum mission and Landsat-D/D' mission) and the upcoming demonstration of shuttle repair to be performed on the solar maximum satellite in the first quarter of 1984. Leasecraft can be identified as a system, comprising a low orbit space platform, an operations control center, user accommodations, and services such as payload interfaces, documentation, and ground support equipment and procedures. The combination of these elements facilitates the use of the space environment by both the space and nonspace oriented user. Early potential applications of Leasecraft include the processing of pharmaceuticals and materials, satellite-aided search and rescue, data collection, and support of NASA's astrophysics programs. Initial assessments made concerning the benefits to users and the cost of providing these benefits indicates that Leasecraft can provide needed services at very competitive rates. The leasing arrangement is cost effective as compared with present spacecraft platform development and cost assessment techniques.     

Mission-oriented theory for ISTP

The goal of mission-oriented theory is to develop techniques and models which can be used by experimentalists and theorists to interpret spacecraft measurements, deducing from them the maximum amount of information about both local and large-scale dynamics. To be effective, theorists and experimentalists must express their results in a common format. A reasonable starting point is for mission theorists to adopt the format currently used by experimentalists. To this end we have developed new diagnostics for plasma kinetic simulations, which display the results in formats very similar to those commonly used to present satellite wave and particle measurements. We have used a simulation of broadband electrostatic noise to demonstrate how, by comparing simulation results with observations, we can infer quantities which cannot be measured, such as the wave mode. We are also developing the capability of creating data streams from virtual spacecraft located in the simulation region. For example, we used a kinetic magnetopause simulation to explore the ways in which simulations can assist in the interpretation of single and multiple satellite measurements in regions of strong spatial inhomogeneity. To address directly the mission objective of measuring global transport, global MHD models are employed. In order to facilitate the initial comparison with ISTP satellites, time histories of simulated generic states of the magnetosphere will be stored on optical disks; these will then be used to create dynamical displays of both local parameters and the global configuration. Finally we demonstrate the use of data based phenomenological magnetic field models in single particle trajectory calculations to describe large-scale kinetic properties of the magnetospheric plasma. We briefly discuss the success of large-scale kinetic calculations in delineating the structure of the plasma sheet, and present some possible ISTP research initiatives which can be used to determine the structure of the very distant tail and the entry of plasma into the tail.     

Automatic Target Recognition: Some Considerations

Machine analysis of aerial reconnaissance data is desirable. New acquisition techniques, equipment, and sensors, plus a growing demand for rapidly obtained, accurate information necessitate machine performance of tasks presently accomplished by observers and interpreters. Many of these tasks can be described as pattern recognition or information processing functions. This paper discusses significant problems encountered when attempting to identify objects or regions automatically from aerial photography. Problems include sensor distortions, variations in target environment, and concepts of design and ?teaching? of an actual device. Operational requirements such as processing speed and flexibility restrict the types of solutions available. Approaches to target recognition with relative merits and shortcomings are presented; these include shape correlation, feature extraction, and image quantization. The effect of mission requirements on system parameters is discussed. A bibliography is included.     

Space Station Payload Accommodation

The unique characteristics of the Space Station are changing the ways payloads are designed and accommodated for orbital flight. Station accommodations need to be versatile and operationally flexible to permit integration of many types of equipment in a variety of modes; and autonomous to render each payload independent or invisible to the rest of the system and other mission equipment. This paper presents the various categories of Space Station payloads, the user facilities that are being designed to accommodate them, illustrates through scientific and commercial scenarios the utilization of those facilities, and identifies the factors that must be considered to make the Space Station an effective tool for the users.     

Gravity Recovery and Interior Laboratory (GRAIL): Mapping the Lunar Interior from Crust to Core

The Gravity Recovery and Interior Laboratory (GRAIL) is a spacecraft-to-spacecraft tracking mission that was developed to map the structure of the lunar interior by producing a detailed map of the gravity field. The resulting model of the interior will be used to address outstanding questions regarding the Moon’s thermal evolution, and will be applicable more generally to the evolution of all terrestrial planets. Each GRAIL orbiter contains a Lunar Gravity Ranging System instrument that conducts dual-one-way ranging measurements to measure precisely the relative motion between them, which in turn are used to develop the lunar gravity field map. Each orbiter also carries an Education/Public Outreach payload, Moon Knowledge Acquired by Middle-School Students (MoonKAM), in which middle school students target images of the Moon for subsequent classroom analysis. Subsequent to a successful launch on September 10, 2011, the twin GRAIL orbiters embarked on independent trajectories on a 3.5-month-long cruise to the Moon via the EL-1 Lagrange point. The spacecraft were inserted into polar orbits on December 31, 2011 and January 1, 2012. After a succession of 19 maneuvers the two orbiters settled into precision formation to begin science operations in March 1, 2012 with an average altitude of 55 km. The Primary Mission, which consisted of three 27.3-day mapping cycles, was successfully completed in June 2012. The extended mission will permit a second three-month mapping phase at an average altitude of 23 km. This paper provides an overview of the mission: science objectives and measurements, spacecraft and instruments, mission development and design, and data flow and data products.     

Touring the Saturnian System

The Cassini mission to Saturn employs a Saturn orbiter and a Titan probe to conduct an intensive investigation of the Saturnian system. The orbiter flies a series of orbits, incorporating flybys of the Saturnian satellites, called the ‘satellite tour.’ During the tour, the gravitational fields of the satellites (mainly Titan) are used to modify and control the orbit, targeting from one satellite flyby to the next. The tour trajectory must also be designed to maximize opportunities for a diverse set of science observations, subject to mission-imposed constraints. Tour design studies have been conducted for Cassini over a period of several years to identify trades and strategies for achieving these sometimes conflicting goals. Concepts, strategies, and techniques previously developed for the Galileo mission to Jupiter have been modified, and new ones have been developed, to meet the requirements of the Cassini mission. A sample tour is presented illustrating the application of tour design strategies developed for Cassini. This revised version was published online in August 2006 with corrections to the Cover Date.     

CCSDS空间包在MOIMS领域中的应用

为了适应未来航天任务的发展,构建以服务为导向的、开放的、可重用的航天器任务操作系统,分析了CCSDS(Consultative Committee for Space Data Systems,空间数据系统咨询委员会)中MOIMS (Mission Operations and Information Management System,任务操作及信息管理系统)领域的任务操作服务框架的原理、层次结构及优点,对任务操作相关的通用服务、功能服务、COM(Common Object Model,通用对象模型)及MAL(Message Abstraction Layer,消息抽象层)对服务的抽象化描述方法进行了研究.MAL向任务操作相关的服务提供了通用的服务模型框架,所有服务均可用MAL消息格式进行规范化的描述,在此基础上建立了MAL消息格式与CCSDS空间包的映射关系,从而以CCSDS空间包为信息栽体实现了航天器与地面系统间的任务操作通信,可以作为以服务为导向的任务操作系统实际工程应用的参考.     

Fine Resolution Epithermal Neutron Detector (FREND) Onboard the ExoMars Trace Gas Orbiter

ExoMars is a two-launch mission undertaken by Roscosmos and European Space Agency. Trace Gas Orbiter, a satellite part of the 2016 launch carries the Fine Resolution Neutron Detector instrument as part of its payload. The instrument aims at mapping hydrogen content in the upper meter of Martian soil with spatial resolution between 60 and 200 km diameter spot. This resolution is achieved by a collimation module that limits the field of view of the instruments detectors. A dosimetry module that surveys the radiation environment in cruise to Mars and on orbit around it is another part of the instrument.This paper describes the mission and the instrument, its measurement principles and technical characteristics. We perform an initial assessment of our sensitivity and time required to achieve the mission goal. The Martian atmosphere is a parameter that needs to be considered in data analysis of a collimated neutron instrument. This factor is described in a section of this paper. Finally, the first data accumulated during cruise to Mars is presented.     

New Developments in Radar and Radio Sensors for Aircraft Navigation

Recent developments in airborne Doppler and ground mapping navigation radars and ground and satellite based radio systems are described. Simultaneous lobing and slope tracking techniques can remove the well-known Doppler sea bias error in fast and slowly moving vehicles. Doppler velocity information can be extracted from coherent forward-looking mapping radars, and high position fixing accuracy can be achieved by synthetic aperture radars. In radio navigation systems, such as Loran, Omega, and satellite systems, direct-ranging and differential techniques greatly reduce the geometric dilution and propagation effects which have plagued conventional radio navigation systems. The advantages gained by mixing of the data from these and other navigation sensors in a digital multisensor system are discussed and approaches for processing these data are suggested.     

航空发电机传动轴扭转振动测试实验研究

航空发电机是飞机任务系统电能的主要来源,也是任务系统甚至载机正常工作的保证。考虑到任务系统工作时具有脉冲电流的特性,利用地面实验设备,模拟发电机的实际运行状态和载荷情况,进行发电机的动态测试实验,得到了脉冲电流作用下发电机弹性传动轴冲击扭转振动曲线。通过对实验结果的对比分析,证实了任务系统工作时的脉冲电流是发电机传动机构扭转振动的主要激励源,同时也是弹性传动轴出现断轴故障的主要原因;适当增大弹性轴的轴径,可以改善系统的固有特性,从而有效缓解弹性轴扭转力矩的振动峰值。     

嫦娥二号再拓展试验测定轨精度研究

基于＂嫦娥二号＂卫星再拓展试验的设计轨道,研究各种摄动力对轨道确定精度的影响,得出的结论是：若要达到km量级的轨道确定精度,必须考虑除天王星和海王星之外所有大行星以及日月的质点引力。文章进一步利用数值分析法研究再拓展任务的轨道确定精度,分析结果表明：基于目前的测控条件,使用30 d以上的测轨弧段可以得到稳定可靠的轨道解,而短弧（小于20 d）稳定轨道的获取需要VLBI（甚长基线干涉）测轨数据支持;当＂嫦娥二号＂距离地球700万km时,测控精度可优于30 km;虽然每天测轨弧段的增加可以改善轨道精度,但是当增加到8 h以上时,定轨精度将不再有明显改善。     

The canberra high altitude mission platform

This presents the capabilities of two English Electric Aviation Canberra aircraft owned by High Altitude Mapping Missions, Inc. These aircraft are available for high altitude commercial, government, and scientific missions. The basic specifications of the Canberra are provided and compared to other high-performance jet aircraft falling into the same category. This describes the high altitude flight characteristics and mission capabilities of the Canberras. The aircraft are configured to conduct up to eight-hour flight operations with up to six hours at 50,000 feet altitude. Shorter missions can be conducted at higher altitudes. Potential missions include: IFSAR, magnetic field mapping, gravity field mapping, imaging (SAR, IR, & hyper-spectral), LIDAR, communications relay, dropsonde deployment, hybrid rocket launching, severe storm monitoring, and disaster monitoring. Canberra high altitude operations have minimal weather impact on missions, are free from flight constraints imposed by air traffic control, can do large area coverage, and long mission times.     

直升机加装数据中继设备的设计与分析

直升机因具有低速、机动灵活、起降要求低等特点而得到广泛使用,而空中数据中继转发设备的加改装将进一步拓展直升机任务面。基于某型直升机加装空中数据中继转发站的实际工作,对加改装设计过程进行分析,计算了各部件安装后的受力强度,给出了加装设备结构强度和质心的计算方法,并对加装设备与直升机的电磁兼容性能和设备本身的通信性能进行了分析。结果表明,空中数据中继转发站加装后符合法规要求的结构强度和电磁兼容性等适航要求,且通信性能满足超视距数据中继任务要求。因此,该项工作可为同类型改装工作提供参考和借鉴。     

塔康仿真系统的设计

塔康是战术空中导航系统,能完成测距和测位的任务。塔康仿真器是具有塔康设备功能的计算机仿真系统,它可以代替塔康设备参与航空电子系统的综合试验,而且能取得很好的效果。本文在分析塔康工作原理的基础上,对塔康仿真器的硬件结构和软件设计做了较为详细的介绍,同时,对塔康信标的仿真也做了扼要的说明。     

A Laser Device for Remote Vibration Measurement

A laboratory study has been made of concepts that utilize a laser for a vibration measurement device. The laser beam possesses the needed characteristics for a spatially directed carrier capable of detecting and transmitting vibration information to remote data processing equipment; furthermore, such a laser vibration measurement device can accomplish the measurement without mechanical contact with the structure under test. The measurement technique utilizes the Doppler shift produced on a wave reflected from a surface vibrating normal to the beam path. Several techniques are available for detecting the Doppler shift; optical heterodyne or homodyne detection and microwave subcarrier modulation methods are candidates for practical instruments. Preliminary results from laboratory experiments indicate Optical heterodyne detection to be the most practical method with present state-of-the-art equipment.     

Future NASA spaceborne SAR missions

Two Earth-orbiting radar missions are planned for the near future by NASA-Shuttle Radar Topography Mission (SRTM) and LightSAR. The SRTM will fly aboard the Shuttle using interferometric synthetic aperture radar (IFSAR) to provide a global digital elevation map. SRTM is jointly sponsored by NASA and the National Imagery and Mapping Agency (NIMA). The LightSAR will utilize emerging technology to reduce mass and life-cycle costs for a mission to acquire SAR data for Earth science and civilian applications and to establish commercial utility. LightSAR is sponsored by NASA and industry partners. The use of IFSAR to measure elevation is one of the most powerful and practical applications of radar. A properly equipped spaceborne IFSAR system can produce a highly accurate global digital elevation map, including cloud-covered areas, in significantly less time and at significantly lower cost than other systems. For accurate topography over a large area, the interferometric measurements can be performed simultaneously in physically separate receive systems. Since LightSAR offers important benefits to both the science community and US industry, an innovative government-industry teaming approach is being explored, with industry sharing the cost of developing LightSAR in return for commercial rights to its data and operational responsibility. LightSAR will enable mapping of surface change. The instrument's high-resolution mapping, along with its quad polarization, dual polarization, interferometric and ScanSAR modes will enable continuous monitoring of natural hazards, Earth's surface deformation, surface vegetation change, and ocean mesoscale features to provide commercially viable and scientifically valuable data products. Advanced microelectronics and lightweight materials will increase LightSAR's functionality without increasing the mass. Dual frequency L/X-band designs have been examined     

新形势下航天测控系统建设转型思考

针对航天测控系统建设目前所面临的角色定位转换、功能体制转型,以及任务要求不断提高、测控技术快速发展等新形势和新要求,分析了航天测控系统的建设管理和功能体制现状,提出了坚持一体规划、推动系统建设,坚持与时俱进、提升建设标准,坚持信息主导、突出建设重点的系统建设转型思路.并在此建设思路的基础上,提出了装备研制向型谱化、标准化转型,维修保障向全寿命、体制化转型,软件开发向产品化、装备化转型,以及推进一体化网络化、强化综合能力、重视安全性可靠性等建设举措.