重力异常对航天测量船惯导姿态测量的影响与补偿

分析了重力异常产生的原因,根据有害加速度对于惯导系统的影响,建立了基于重力 异常的惯导比力误差方程及姿态误差测量模型。结合航行试验分析了影响与应用效果,试验 结果表明,高精度的姿态测量系统中必须考虑重力异常的影响,利用该方法可以基本消除重 力异常的影响,部分海域可使惯导姿态精度提高约20″,对提高航天测量船外测精度具有重 要意义。     

基于递推最小二乘算法的惯导姿态误差动态标定方法

在分析最小二乘算法原理的基础上,提出了一种基于递推最小二乘算法的惯导姿态误 差动态标定方法,建立了计算模型,进行了仿真分析。仿真结果表明,该方法具有较高的解 算精度和计算效率,航向误差解算精度优于35″,水平误差解算精度优于015″。该方 法解决了动态条件下惯导姿态误差实时标定的技术难题,对提高惯导姿态测量精度和测 量船外测精度具有重要意义。     

GPS实时校正惯导系统的必要性分析

惯导测量系统测量精度高,但存在累计误差,用GPS的位置信息来定期校正惯导系统的位置,由于信息的利用率低,其校正的效果并不理想。惯导系统具有很强的独立性,系统会排斥校正的干扰而重新恢复到原来的平衡状态,致使GPS校正后的位置出现周期性变化。本文分析了实时校正的必要性,不仅保持惯导系统的精度．还扩展系统的应用前景。     

主动雷达与惯导设备安装夹角的标校

针对主动雷达与惯导设备安装夹角引起的测角误差问题，提出了一种高效、高精度的标校方法。采用差分全球定位系统(Global Positioning System,GPS)分别测量目标和雷达在大地坐标系中的位置信息，并转换到目标地理坐标系中；同时通过雷达和惯导测量的雷达坐标系下的目标角度、距离信息，建立目标地理坐标系和雷达坐标系的转换方程，计算出雷达和惯导在目标地理坐标系下的安装夹角。性能分析和仿真结果表明，在确保差分GPS坐标、惯导输出姿态角和雷达测量角精度的条件下，所提方法能有效和高精度的测量出安装夹角。该方法通过了外场试验标定和机载试验验证，可推广到车载或机载雷达与惯导设备的安装夹角标校中。     

基于角速度的捷联惯导系统姿态算法研究

姿态矩阵的更新算法优劣直接影响了捷联惯性导抗系统（strapdowninertialnavigationsystemiSINS）的精度。本文针对以光纤陀螺为代表的输出为角速度的捷联惯导系统，研究了其姿态解算算法，对欧拉角法、方向余弦法，四元数毕卡解法、四元嫩龙格率塔解法、基于角速度的优化等效旋转矢量法进行了分析，并对后三种方法在三轴摇摆条件下进行了仿真。本文对光纤捷联．膀导系统的姿态算法研究具有重要诚意义o。。。。。     

船载测量雷达稳定回路作用分析

分析了船载测量雷达陀螺稳定回路的作用机理，以及稳定回路作用前后雷达跟踪稳定性。用Matlab对稳定回路作用前后跟踪回路进行了仿真，对分系统误差分量和随机误差分量进行了跟踪精度分析，并通过两次测量任务数据处理结果的比较，证明船摇较小时，加入稳定回路会造成跟踪精度的降低。     

光纤陀螺抗振技术研究

针对振动对光纤陀螺性能的影响，提出改善机械结构与信号处理相结合的抗振技术。根据机械振动机理，应用有限元理论对结构的分析，改善光纤环骨架的设计，提高其共振频率，达到了船舶使用环境的要求；分析了振动对光纤环的调制机理．采用小波滤波的方法对受振动噪声污染的陀螺输出进行信号处理，比较不同小波基的滤波效果，得到适合实际使用的最优选择。     

基于振动特性的光纤陀螺结构件改进设计

光纤陀螺作为导航元件应用时，载体振动将对陀螺的精度产生影响，本文以舰船为载体环境，初步探讨了光纤陀螺的振动特性。通ANSYS有限元振动模态分析，研究了光纤陀螺的结构体共振频率以及振动对陀螺性能的影响，并在此基础上提出了陀螺结构件设计的改进方法。     

Y／JTG-1A陀螺经纬仪在矿山竖井中的应用

本文介绍了Y／JTG-1A陀螺经纬仪为自主式、全天候的精密定略仪器，可快速实现真北方位角的测量。实践证明，Y／JTG-1A陀螺经纬仪在发恩德矿业有限公司沙沟矿区竖井中定向，实际贯通测量结果证明，能够达到平巷间贯通精度、提高效率及降低劳动强度等。     

信道群时延特性的工程测量

信道的群时延指标对跟踪系统的测量精度和通信系统的信号质量都十分重要。但该项指标的测试通常因缺乏专用仪器而不能进行,影响了设备误差的分析和系统潜力的发挥。本文介绍利用常用的仪器,采用调制法进行群时延测量的构想,并着重解决了调制器引入的群时延漂移。论述了测量的合理性和调制频率选择的依据,对测量结果进行了分析。     

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,     

Domino Effect on Electricity and Coal Prices

In the middle of last December, the key purchase contracts for coal used in power generation in 2008 were signed, reflecting a demand for more than 1.085 billion tons. It is important to note that the country＇s five biggest power producers, China Huaneng Group, China Guodian Corporation, China Power Investment Corporation, China Huadian Corporation and China Datang Corporation, had settled on the prices on their purchase contracts, and they are expected to consume 290 million tons of coal for generating electricity,     

Slimmed May Day Holiday

Last November the State Council of China decided to renew its holiday system by reducing the seven-day May Day holiday to three days and introducing three new one-day public holidays, namely the Qingming Festival, Dragon Boat Festival and Moon Festival. By doing so, the three golden-week holidays that were introduced in 1999, namely the Spring Festival, May Day and National Day, could be better distributed.