红外预警卫星直视地表波段选择及探测能力

建立了红外预警卫星直视地表（See-To-Ground,STG）波段探测能力计算模型,并仿真研究了STG最佳探测波段范围以及该波段在导弹预警中可能具备的能力。首先建立了固体、液体导弹尾焰红外辐射模型、地球/大气环境特性模型、点目标辐射通量表观对比度模型、预警卫星系统噪声模型和最低探测高度模型;其次,利用上述模型分析了固体和液体导弹尾焰的表观对比光谱分布规律,认为将STG波段选定为2.86~3.0 m最具合理性;然后,通过分析液体和固体导弹尾焰在该波段的表观对比度光谱随高度的变化规律,初步探讨了STG波段的导弹探测能力;最后,通过分析不同条件下预警卫星对导弹的首次探测高度,系统研究了SBIRS-GEO预警卫星在STG波段的探测能力。研究结果表明:STG波段对固体导弹则具有较强的早期预警能力,而对液体导弹的早期预警能力则相对较弱。     

地球同步轨道红外预警卫星仿真模型研究

天基红外预警卫星通过红外传感器探测弹道导弹主动段飞行时散发的红外尾焰,能在早期发现和跟踪弹道导弹目标。其中地球同步轨道卫星由于轨道高度高,因而具有更广的探测范围,是目前广泛使用的一种红外预警卫星,也是反导系统仿真中的重要研究对象。文中主要描述了一种地球同步轨道卫星探测功能的仿真建模方法,重点论述了地球同步轨道卫星目标发现条件并推导了探测范围计算公式,对于红外预警卫星的仿真及规划等问题的研究具有一定意义。     

基于红外特性的弹道导弹助推段预警探测能力仿真

针对弹道导弹助推段的主要红外辐射特征,分析了尾焰羽流的结构、形状、大小和持续时间,以及大气对红外探测的影响;根据预警卫星探测器最大作用距离模型及信噪比（SNR）,结合给定参数对预警卫星探测器技、战术指标进行了仿真,给出了提高弹道导弹探测能力的方法。     

战术弹道导弹防御中的红外探测预警分析

在分析战术弹道导弹飞行弹道特点的基础上,说明了探测助推段的强大尾焰是对战术弹道导弹进行红外预警的主要手段。介绍了美国DSP预警卫星的工作机理,给出了一种预警模型的建立方法。     

导弹尾焰红外辐射运动变化探测研究

针对导弹尾焰红外辐射的探测问题,分析了导弹的运动状态对尾焰红外辐射探测的影响,建立了导弹尾焰红外辐射探测模型。主要研究了直线、水平圆弧及爬升和下滑的运动状态的探测模型,并进行了仿真,得出了三种运动状态下导弹尾焰红外辐射运动探测的变化规律。     

导弹防御预警系统仿真分析

导弹防御预警系统的主要作用就是及时发现来袭导弹,为弹道导弹防御系统实现识别、跟踪与拦截导弹提供必要的信息.通过分析研究,初步分析了预警卫星和远程预警雷达的探测性能,及两者在导弹预警过程中的接力关系.分别建立了预警卫星和远程预警雷达对弹道导弹探测的数学模型,针对短程和洲际弹道导弹进行仿真分析,计算出了预警卫星和预警雷达对不同射程导弹所能提供的预警时间.     

基于燃速的助推段固体弹道导弹红外特性分析

速燃助推作为应对红外预警卫星的有效手段,直接关系导弹防御系统的作战效能。论述了预警卫星工作原理,总结了速燃助推技术,建立了发动机喷管出口温度、导弹蒙皮温度和导弹尾焰温度特性与发动机燃速的数学模型,采用定量与定性相结合的方式仿真分析了助推段固体弹道导弹的红外特性与燃速的关系,探讨了速燃条件下减小导弹红外辐射特性的有效措施。     

国外早期预警卫星发展透视

导弹预警卫星是一种较特殊的成像卫星，通过对导弹发射主动段羽焰的红外辐射等探测成像，将红外辐射图像信号变换为数字化电信号传输，经处理识别后提供敌方导弹袭击的预警信号。预警卫星和平时期可用于监视导弹试验、航天发射活动，战争时期则专门监视和跟踪敌方弹道导弹发射，从而实现在导弹主动段早期预警的目的，可以使预警时间增加到30min左右。     

红外烟幕对高轨星载红外探测器干扰效能评估

为降低导弹预警卫星对弹道导弹预警定位能力，从分析导弹预警卫星红外探测系统入手，介绍了通过伴星或火箭施放红外烟幕对其进行干扰的机理，并从烟幕对红外辐射的吸收能力、散射能力以及烟幕自身红外辐射三个方面评估了烟幕对红外探测系统的干扰能力，并最终以目标与环境的对比度的改变来衡量干扰效果。     

基于STK的预警卫星部署与性能分析

预警卫星对导弹的早期预警是反导防御系统有效作战的关键环节,而红外预警卫星就是实现弹道导弹早期预警的有效手段。利用卫星工具包（STK）仿真工具,研究红外预警卫星部署的方法,并通过STK仿真出来的数据分析其探测能力。该方法可得到针对特定热点地域反导预警卫星的合理部署方案。     

TEDA—S16卫星接收地面站的设计

本文简要介绍了天津经济技术开发区TEDA-S16卫星接收地面站前端的设计,突出解决了定向服务电视节目的传送问题。在卫星接收部分,对ASIASAT Ⅰ星、BS-3a星、DFH-2a星、IS-V星的有关资料作了介绍,并对其接收链路进行了分析与计算。     

Disaster watch

Satellites have collected images of natural and man-made disasters for decades, but a satellite system has never been dedicated to disaster monitoring, until now. The author reports on the Disaster Monitoring Constellation, a new departure for microsatellites     

地面粗糙起伏对分布式小卫星SAR回波信号相关性影响分析

该文讨论了地面的粗糙和起伏对分布式星载SAR回波信号相关性的影响。首先利用小平面单元理论建立了粗糙地面的散射模型,并对其统计特性进行了分析;之后,以服从瑞利分布的二维相关随机过程作为地面的起伏模型对分布式星载SAR起伏地面回波信号的相关性进行了仿真分析。仿真结果表明当分布式小卫星基线垂直航向分布时,地面的起伏对回波间的相关性影响较大;而分布式小卫星基线沿航线分布时,地面起伏对其回波间的相关性影响则相对较小。     

Meteorological applications of remote sensing from satellites

Satellites provide meteorologists with a data source unmatched at comparable spatial and temporal coverage by any existing or practical alternate source. There are limitations, however, both instrumental and fundamental, imposed on the achievable resolution and accuracy. Current and promising future contributions to meteorology from satellite-borne sensors are discussed, with emphasis on performance and the limitations thereto. The discussion covers 1) synoptic meteorology where satellite observations of clouds provide measures of winds, cyclogenesis, and rainfall estimation; 2) atmospheric profiling wherein vertical profiles of temperature, humidity, and certain gaseous constituents are provided; 3) radiation budget or the energy exchange between the earth and the space-sun environment; and 4) surface features of importance to meteorology-temperature, soil moisture, and sea ice coverage. Satellites will be extensively used as data collectors and relays from in situ instruments on buoys, balloons, and fixed earth sites. The accuracy and coverage of such observations, however, will be determined by the in situ sensors and not by the satellite. They are therefore not discussed here.     

Ku波段卫星广播中雨衰现象的研究

对Ｋｕ波段电波传播的特点进行了分析,根据ＣＣＩＲ建议的方法和接收天线的仰角及电波的极化角数值,对Ｋｕ波段的雨衰进行了定量计算,并将雨衰曲线标在全国地图之上,根据雨衰曲线可以对卫星Ｋｕ波段转发器天线的波束图进行优化设计,也可以对卫星接收系统进行合理的设计以减少降雨产生的影响。     

Environment-sensing climate change

The growing international effort to monitor what progress is doing to the planet is examined. The top priority has been identified as a broad one encompassing the climatic effects of clouds, water vapor, precipitation, and solar radiation. The infrared, optical, and microwave sensors that will be used are discussed, focusing on the information that will be obtained in each region of the spectrum. The new technique of limb sounding, using millimeter-wave radiation, is described. Some of the factor affecting climate, particularly ocean circulation, aerosols, and methane, are examined. Satellites and instruments are discussed     

Security from space

Satellites have gained a prominent role in the US's toughened homeland protection plan and many companies are set to benefit. Satellites have an important role in monitoring and protecting infrastructure and many companies are planning to capitalise on America's emergent homeland security market. According to an October 2002 study by the Electronics and IT Association, they could be competing for up to /spl divide/n-worth of business, which could grow to $12bn by 2008. Of course, only a small percentage of this would go to satellite companies, but this has not stemmed the flow of new ideas. As part of the Homeland Security initiative, NASA and the Department of Transportation are considering how commercial satellite imagery could be applied to other potential terrorist targets such as airports. By developing interactive digital maps, they hope to illustrate their use not only in planning airport security improvements, but also in guiding rescuers through the devastation following an incident. Eventually, it is envisaged that real-time ground radar data could be incorporated to help detect suspicious aircraft or vehicle movements.     

发达国家的几种卫星应用考虑

介绍了加拿大、美国、德国、法国不同的卫星应用考虑。加拿大拟用2颗卫星在2007年前后获得近乎全球高精度的地球高低数据,美国着重于开发全球性的侦察和作战用的卫星群,德国和法国则试图用一发数收小卫星来解决SAR/MTI。     

分布式小卫星SAR顺轨基线解耦合分析

地面动目标检测是分布式小卫星SAR研究的热点之一,但是分布式小卫星的空间构形导致混合基线的存在,使得地形变化和地面目标运动引起的相位难以区分以致从地面杂波中发现动目标非常困难。该文利用矢量法分析了基线耦合产生的原因,研究了一种能够实现顺轨基线解耦合的轨道构形,计算和仿真表明该文的方法能够有效地把影响动目标检测的垂直航迹基线引起的相位去除。     

Digital image-processing activities in remote sensing for earth resources

The United States space program is in the throes of a major shift in emphasis from exploration of the moon and nearby planets to the application of remote sensing technology toward increased scientific understanding and economic exploitation of the earth itself. Over one hundred potential applications have already been identified. Since data from the unmanned Earth Resources Technology Satellites and the manned Earth Resources Observation Satellites are not yet available, the experimentation required to realize the ambitious goals of these projects is carried out through approximation of the expected characteristics of the data by means of images derived from weather satellite vidicon and spin-scan cameras, Gemini and Apollo photographs, and the comprehensive sensor complement of the NASA earth resources observation aircraft. The extensive and varied work currently underway is reviewed in terms of the special purpose scan and display equipment and efficient data manipulation routines required for high-resolution images; the essential role of interactive processing; the application of supervised classification methods to crop and timber forecasts, geological exploration, and hydrological surveys; the need for nonsupervised classification techniques for video compaction and for more efficient utilization of ground-control samples; and the outstanding problem of mapping accurately the collected data on a standard coordinate system. An attempt is made to identify among the welter of "promising" results areas of tangible achievement as well as likely bottlenecks, and to assess the contribution to be expected of digital image-processing methods in both operational and experimental utilization of the forthcoming torrent of data.