基于运动方程的动态模拟方法

通过分析点目标的矢径运动方程,提出基于运动方程的动态模拟方法,可实现距离和速度的 精确相关并实现深空的超距离模拟。给出了“自检模拟源”和“基地模拟试验”两种方案及误差修正 方法,为测控信号的动态模拟提供了一种新方法。     

采用闭环双口RAM实现深空动态模拟源的设计

深空探测具有时延长、运动速度大以及信号强度低的技术难点。在对上述技术难点进 行分析的基础上,提出了对深空动态模拟的解决办法：通过利用闭环双口RAM来解决模拟时 延较长的问题;改变读出双口RAM数据的速率来模拟卫星的运动速度;控制数控衰减器来模 拟深空的信号强度。实际的工程应用证明上述实现方法有效可行。     

一种应用于深空通信的微弱信号捕获算法

针对低信噪比、高动态条件下深空测控通信信号捕获概率低以及复杂度较高的问题,首先分析了深空测控通信信号捕获的难点以及信号循环平稳特性,然后在此基础上提出了一种基于循环相关的新算法。计算机仿真结果证明新算法捕获门限达24 dBHz,适应频率动态达800 Hz/s;新算法较传统的捕获算法,在相同门限条件下的频率动态适应范围提升了约两个数量级。该方法已被应用于我国第一个深空测控站的建设,工作性能稳定可靠,有效地解决了低信噪比下深空站抑制载波信号的捕获问题。     

一种高精度动态测控信号模拟器

根据测控系统对动态模拟器的要求,即模拟动态范围宽、模拟精度高、逼真度高,设计了采用两级数字存储器对信号进行粗细时延组合控制的转发式模拟器。根据运动方程高逼真度地模拟飞行目标的动态特性,该模拟器可以实现距离模拟范围千万公里时,精度优于1 cm;速度模拟范围每秒几十公里时,精度优于1 mm/s的高精度动态模拟。     

Ka频段大口径天线阵系统及关键技术

地基直接深空测控通信/深空探测难题均在于长达数亿公里的超远距离带来的巨大传输损耗。提出了基于Ka频段分布式大口径天线阵的地基直接测控通信/深空探测设想,探讨了其应用模式及工作机理,对其中共同的关键技术Ka频段上行超大功率空间合成给出了解决措施,具体包括设备自身的ps量级时延稳定性设计、对流层延迟ps量级实时修正、空间传输距离的ps量级预测等。     

角跟踪信号的动态模拟

为了检验天线伺服反馈源系统的性能和状态,要对角跟踪信号进 行动态模拟。根据天线方向图中角度偏移与和差信号幅度的对应关系,通过控制和差信号幅 度从而改变角度偏移,可以对角跟踪性能进行动态模拟。介绍了角度模拟在工程中的实现方 法,分析了影响模拟精度的因素。实际工程应用验证了该方法的有效性。     

基于高性能集群平台的VLBI处理系统设计

角位置是深空探测航天器导航定位的重要观测量信息,相对于获取航天器距离、速度信息的统一载波测量体制,甚长基线干涉测量(Very Long Baseline Interferometry,VLBI)技术的原始数据量呈几何式增长,海量数据的实时、准实时处理对航天器高精度导航定位提出了新的挑战。依托中国深空网干涉测量中心,论述了基于高性能集群平台环境的航天器干涉测角数据相关处理系统的设计实现,并利用探月工程的实测数据进行了验证分析。分析结论对推进我国深空网干涉测量信号处理中心建设、优化相关处理系统资源配置具有一定的参考价值。     

多站制CW雷达目标动态模拟器设计

针对多站制连续波（CW）雷达工作特点,设计了一种CW雷达目标动态模拟器,满足多站连续 波测 量系统动态模拟联试的需求。采用高性能CPCI工控机作为模拟器硬件平台,信号处理单元 以CPCI板卡为载体,模拟控制信息依据弹道数据生成。模拟器通过控制测距信号的时间延迟 ,实现目标距离变化的模拟;通过载波频移控制,实现目标速度的模拟;通过数控衰减器控 制模拟信号的幅度,实现目标信号强弱的模拟。通过多站制测量系统动态模拟联试,验证了 模拟器的有效性和距离与速度的相关性。     

动态目标信号模拟器的设计及实现

为满足地面测控设备联试、功能检查和训练需要,研制了一种能模拟运动目标转发信号、方便而廉价的模拟器.根据测控设备的测距测速原理,阐述了利用延迟测距音实现距离模拟、在转发载波及测距音上加多普勒频偏实现速度模拟的方法,在以PCI总线和在线可编程门阵列(FPGA)为架构平台的信号处理分机中,实现对转发信号的解调、延迟、加多普勒、调制转发.最后对实际试验结果进行了评估,表明经过改进方法后,模拟器可以减小模拟误差,可在实际中使用.     

馈源整体制冷技术在深空测控系统中的应用

深空探测器通信距离遥远,其返回信号微弱,因此要求接收天线具备尽量高的品质因数（G/T）。下行链路设备工作在低温环境中,有利于降低噪声温度,提高系统G/T值。针对35 m深空测控天线,首先分析了Ka频段天线增益、外部和内部噪声;在此基础上提出了Ka频段馈源整体制冷方案,并对馈源不制冷和馈源整体制冷两种方案进行了比对分析;最后总结了超低温馈源设计和制造关键技术。馈源整体制冷系统噪声温度测试结果小于45 K。分析表明采用馈源整体制冷方案能够提升系统G/T值1.03 dB,35 m深空测控天线Ka频段接收能力提高约21%。     

Brown＇s Blossom in Britain-China

The overall strategic relationship between U.K. and China is ＂better than ever＂, China- Britain relations have maintained good momentum, with increased high-level exchanges and the reinforcement of strategic mutual trust, with more room for growth in the future.     

Challenge and Opportunity Go Hand in Hand——What Global Economic Agitation Brings to the China's Economy?

Domino effects of the global finance agitation As the origin of the subprime crisis,US financial institutions lost USS45 billion last year,accounted for over half of the total US,EU & Japan loss.Since January 15th,Chtigroup released its financial statement of the 4th quarter,showing a net deficit of USS9.83 billion,which marked the hisoric high of its quarterly deficit.     

Sinosteel：Extraordinary Moves in Industry Chess

Among the Fortune 500 firms,more and more images from China emerge out.On the 2008 list,Sinosteel Corporation,a landmark group of China industries quietly squeezes into the candidate line.As the largest steel service ＆ trade enterprise,its sales reached at RMB 111.24 billion,with a year-on-year increase of 83.03 percent,and the profit grew by 180.03 percent.On the Sinosteel 2008 Work Meeting,the president Huang Tianwen uttered,＂In the coming year,we will work for US$20 billion sales,and look forward to getting a position in Fortune 500 firms for ourselves.＂     

Walk Through Unusual Five Years—— An Exhibitor＇s Canton Fair Course

When the 103rd Canton Fair is approaching, an old friend of Canton Fair, Li Ying from Jiangsu prov-ince recollected his past five years＇ experiences to the grand trade meeting. Each year is special, with some unforgettable memories colored by the year.     

Jean-Pierre Duprieu： Willing to Be A Legate of Sino-French Business

Estaing, former French president, Valery Giscard d＇Estaing attended Sino-French Economic Seminar held in Shanghai in early April and said that the world center has shifted from the west to the east with many European and US companies entering into Asia, and China has the ability to play an important role in the world stage. Estaing, naming himself＂French Confucian＂, then said in Chinese that a cook-group includes 10 people in ancient Chinese soldier system and the cook is in charge of cooking for them. And people who belong to the same cook are actually ＂Partners＂.     

China''''s Stock Market Wave

The annual meeting of the World Economy Forum was held in Davos,a little town in Switzerland,on January 23rd to the 27th this year,with the theme"the Power fo Collaborative Innovation",over 2500 celebrates from ture political and cconomic circles of more than 80 countries and challengred logether to talk about the future of the global economy in 2008,A Forum for the problems and challenges that face whole world,some of the keywords which drew attention during the event were:the U.S.subprime mortgage crisis,soaring energy prices,the economic slowdown in the U.S.ermerging economic bodies,authority funds and the general unpredictable nature of the global economy.     

Trade Promotion from Neighborhood

If you are considering to trade with companies in Japan or expanding your .business to Japan, we are ready to help from the very beginning.＂ You will find this greeting at the first sight on the Chinese website of Japan External Trade Organization （JETRO）. JETRO has committed itself in delivering highly efficient and quality services to meet the demand of internal and external customs including Japanese companies, hence winning a good reputation in the international trade arena. In recent years, with its priority in advancing business cooperation in South and East Asia, JETRO has made great achievement in promoting trade between China and Japan. Therefore, China＇s Foreign Trade interviewed Mr. Yoichi Maine, Deputy Director General of JETRO BEIJING.     

Auto Parts Market Potential Coming into Surface

Looking at the increasingly fierce competition in the world auto market. global automobile manufacturing industry, taking Europe, the U.S. and Japan as representatives, is gradually forming a new type of relationship, mutual cooperation between whole vehicle and parts manufacturers. We can clearly see that auto parts manufacturers have become independent from the whole vehicle manufacturing companies, which means that the former structure of auto industry has greatly changed, and a new relationship,     

Public Financial Expenditure——A Reflection of the Livelihood Improvement

In recent years.China's public finance put social construction high on the agenda and attaches more importance on livelihood insurance and improvement.The 2003-2007 public financial expenditure reflects a fact that the government isputting more emphasis on livelihood andissues concerning the people.     

Voices from the MPC and CPPCC

"Crucial for economic growth.energy utilization has its role in all economic sectors and every aspect of people's daily life.Now we are in dire need of a new profession,namely energy manager.We not only need to have passion and responsibility,but also a scientific approach to conserve energy and cut emissions.APpropriate legislation should be in place.and a special profession should be introduced to ensure the implementation of these laws and regulations."