激光靶斑阵列数据遥测系统传输特性分析

介绍了一种用于激光靶场试验中测量激光靶斑阵列数据的ＷＹＫ２１遥测系统，对该系统的传输特性，包括数据传输误码率，遥测接收灵敏度和系统功率传输裕量进行了分析研究。     

航天器污染控制与标准化工作

概述了国内外污染控制和标准化工作的现状,介绍了我国和国际标准化组织及美国等用于空间系统、材料和污染控制标准化方面的进展情况,并阐述了根据航天领域的特殊要求建立相关的污染控制标准体系是十分重要的。     

S波段超小型调频发射机

介绍Ｓ波段超小型调频发动机方案的选择，电路设计，结构安排，并对该发射机的稳定性和质量进行了分析，该发射机已通过机载环境条件试验和地面接收机的对接试验，并已通过鉴定，具有９０年代国外同类产品的水平。     

提高航天传输型CCD相机地面像元分辨率方法研究

文章首先对空间传输型遥感相机提高像元分辨率的几种常规和非常规方法做了简介,在分析这些方法的优缺点以及以采样定理为依据分析我国现有CCD相机光学截止频率和CCD采样频率存在的矛盾的基础上探讨了高模式采样技术和超模式采样技术,经过比较这两种采样模式,认为超模式采样技术更具有工程可行性和优越性。然后对超模式采样计算机图像仿真结果进行了分析。     

激波在狭缝中绕射过程研究

针对固体火箭发动机药柱存在裂纹的情况，对运动激波在狭缝中绕射传播的非定常流场进行了计算，得到了清晰的流场变化图谱，从流场图中可分辨出激波在狭缝中的传播过程。对不同深宽比的狭缝进行研究，发现流场结构存在明显差别，在深宽比较小时狭缝内压力波振荡较小，当深宽比超过一定值时狭缝内的压力波产生剧烈振荡。研究结果表明，该方法可很好地描述激波在狭缝中的传播过程。     

基于RBF网络的惯导系统初始对准

建立了惯导系统（ＩＮＳ）初始对准的线性和非线性误差模型。分析了径向基函数（ＲＢＦ）网络的结构和工作原理。研究了ＲＢＦ网代替初始对准中的卡尔曼滤波器的实现方法。通过仿真表明，用神经网络进行初始对准，既可获得与卡尔曼滤波相同的对准精度，又提高了系统的实时性。     

VentureStar… reaping the benefits of the X-33 program

Major X-33 flight hardware has been delivered, and assembly of the vehicle is well underway in anticipation of its flight test program commencing in the summer of 1999. Attention has now turned to the operational VentureStar^TM, the first single-stage-to-orbit (SSTO) reusable launch vehicle. Activities are grouped under two broad categories: (1) vehicle development and (2) market/business planning, each of which is discussed. The mission concept is presented for direct payload delivery to the International Space Station and to low Earth orbit, as well as payload delivery with an upper stage to Geosynchronous Transfer Orbit (GTO) and other high energy orbits. System requirements include flight segment and ground segment. Vehicle system sizing and design status is provided including the application of X-33 traceability and lessons learned. Technology applications to the VentureStar^TM are described including the structure, propellant tanks, thermal protection system, aerodynamics, subsystems, payload bay and propulsion. Developing a market driven low cost launch services system for the 21st Century requires traditional and non-traditional ways of being able to forecast the evolution of the potential market. The challenge is balancing both the technical and financial assumptions of the market. This involves the need to provide a capability to meet market segments that in some cases are very speculative, while at the same time providing the financial community with a credible revenue stream. Furthermore, the market derived requirements need to be assessed so as not to impose unnecessary requirements on the vehicle design that add unreasonable cost to the development of the system, yet provides the right capabilities for new markets that could be triggered by dramatically lower space transportation prices.     

图象压缩技术的发展

图象压缩是信息领域发展中的关键技术之一,本文综述了图象压缩技术的发展,论述了各发展阶段的基本压缩原理、特点及主要实用方法的优缺点。对80年代后期新发展的分数维压缩方法的有关概念、方法及现状着重作了论述。分数维图象压缩方法与VLSI技术的结合,将会对未来的遥感、通讯、导航及一切与图象有关的领域产生重大影响。     

过程体系结构

从系统论的观点出发，明确定义了过程工程领域的基本概念，定义了过程体系结构，采用了一个扩充的ＣＯＳＭＯＳ模型，以支持灵活的过程建模，并在此基础上讨论了过程的工程化支持。     

分形图象学的发展

简述分形几何基本概念及其在图象领域中的应用，包括随机分形模型、混沌动态系统中的分形及迭代函数系统分形模型及其典型应用。