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Table of Content

    25 April 1994, Volume 14 Issue 02 Previous Issue    Next Issue
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    DESIGN AND ESTIMATION OF PERFORMANCE GAIN FOR A DOUBLE NESTED EXTENDED NOZZLE
    Wang Chengxuan(Huaihai Institute of Engineering, Lianyungang 222001)
    1994, 14 (02):  . 
    Abstract ( 1581 )   Save
    This paper described the design method of an extended nozzle with a double nesled exit coned particularly introduced some practical problems to be handled and estimated the performance gain of this nozzle. The lesults show that the nozzle is of higll application value.
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    2-D SEPARABLE MULTI-STEP AMPLITUDE QUANTIZATION WITH EXPONENT RESTRAINT FOR AIRBORNE SOLID-STATE ACTIVE ARRAYS
    Gao Tie(4-th division,Nanjing Research Institute of ElectronicsTechnology, Nanjing 210013)
    1994, 14 (02):  . 
    Abstract ( 1834 )   Save
    n this paper,a design technique of 2-D soparabl3 multi-step amplitude quantization low sidelobe apert ure distribution with exponent restraint for airborne solid-state active phased arrays is proposed. It i3 shod n that this method is' effective to reduce the peak sidelobe levels in horizontal plane and other areas and the kind of T/R modules. Using 2-D separable design idea, the number kinds of column feeding networks can be greatly reduced in engineering application. The. computer simulated results confirm the theoretical analysis.
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    A METHOD OF CALCULATING EXTERNAL HEAT FLUXES ON ARBITRARY SHAPED CONVEX SURFACE OF SPACECRAFT
    Weng Jianhua;Pan Zengfu(Beijing. Institute of Spacecraft System Engineering, Beijing100086)Min Guirong(Chinese Academy of Space Technology, Beijing 100081)
    1994, 14 (02):  . 
    Abstract ( 1934 )   Save
    On the basis of Monte Carlo method,have the results of albedo and infrared view factors of flat plate, hemispherical surface and parabolic surface. Compared with the data of view factors handbook t17, the results show that the program based on Monte Carlo method can be used to calculate orbital heat fluxes of arbitrary shaped convex surfaces of a spacecraft practically and reliably.
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    A RESEARCH OF AUDIO-CODING IN VIDEO CONFERENCE
    Deng Guanglin; Ji Zaogen; Wan Jinsheng(Bening Stallite Station, Beijing 100094)
    1994, 14 (02):  . 
    Abstract ( 1566 )   Save
    Audio-coding technique is one of the important problems of a Video Confelence System. The article describes sub-band adaptivo differential pulse code modulation with a bit rate below 64kbit/s. The transmission quadrature mirror tilters comprise two linear-phase non-recursive digital tilters which split the frequency band illto two sub-bands.The difference signals are quantized to 6 and 2 bit for the lower and higher sub(bands respectively.The adaptive predictors compute predicted signal values for the lower and higher sub-bands respectively. The decoding results show that the restored audio is successful and the odd order form of audio is as same as the even ord e r.
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    ANALYSIS OF MODULATION TRANSFER FUNCTION OF SPACE-BORNE LINEAR ARRAY CCD CAMERA
    Liu Fuan; Wang Mingyuan(Xi' an Space Institute of Radio Techn-llogy 3 Xi'an 710000)
    1994, 14 (02):  . 
    Abstract ( 1507 )   Save
    The major factors affecting modulation transfer function of a space-born, linear array CCD camera are analysed, correlativo calculation formula,calculated results and a number of practical experience data are given. Finally, some values of the modulation transfer functions of foreign linear array CCD cameras are presented.
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    APPLICATION OF ORBITAL MANEUVER TECHNIQUE IN AEROSPACE
    Wu Yushi(Beijing institute of Spacecraft System Engineering, Beijing 100086)
    1994, 14 (02):  . 
    Abstract ( 1849 )   Save
    The Technique of orbit maneuver plays an important role in the field of aerospace, especially for near earth orbit satellite system.The Technique provides a way to solve the problem of inconsistence between satellite requirements and the launch vehicle capability. By using this technique, different launch vehicles could be chosen for the same satellite,operational performances could be enhanced,and application range could be widen.In addition, the general concept of the Technique and its application in the near earth satellite system with some examples are described.
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    SPACE TETHER IN FUTURE SPACE-STATION SYSTEMS
    Zhu Renzhang(Beijing University of Aeronautics and Astronautics, Beijing 100083)
    1994, 14 (02):  . 
    Abstract ( 1508 )   Save
    In the future space-station system,space tethers will play a significant and unique role.Tether technology is one of key technologies to develop space transportation, space research and space applications.
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    MOTION EQUATIONS AND STABILITY CRITERIA OF BODY-PARACHUTE SYSTEM
    Li Dayao(Beijing Institute of Space Maohine and Electricity,Beijing 100076) Li Dazhi(Nantong Coll ege of Medicine, Nantong 226001)
    1994, 14 (02):  . 
    Abstract ( 1568 )   Save
    he calculating trajectory and analyzing motion stability of a body-parac hute system are important problems of design of a recovery jystem of a vehicle. The model of rigid body-rigid body is used instead of body-parac hute system.According to the model,the motion equations and stability criteria of a body-parac hute system are given.
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    COMPARISON OF SINGLE EVENT EFFECTS INDUCED BY SPACE PARTICLE ENVIRONMENT COMPONENTS
    Meng Qingru; Zhao Dapeng;Bac Bairong(Beijing Institute of Satellite Environment Engineering, Bening 100029)
    1994, 14 (02):  . 
    Abstract ( 1499 )   Save
    oth heavy ions and protons in space can cause single event effects (SEE) .The comparison of contributions of heavy ions and protons in several typical conditions to SEEs indicates that trapped protons must be considered in the region adhere trapped protons are greatly intense, and that outside the region, it is not the protons which are the overwhelming majority, but tho heavy ions that predominantly arouse SEEs.
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    NONLINEAR FIT OF SATELLITE FLIGHT TEST DATA FOR OPTICAL SOLAR REFLECTOR
    Qiu Jiawen(Lanzhou Institute of Physics, Lanzhou 730000)
    1994, 14 (02):  . 
    Abstract ( 1565 )   Save
    he curve fit of the function y=a[1-exp (-bx)] has been resolved by combining linear regression and optimum seeking method. The empirical expression for space o ptical property degrada non of Optical Solar Reflector has been obtained from 'the fitting analysis of satellite flight test data of the Optical Solar Reflector developed by China. The longterm space stability of Optical Solar Reflectol has been predicted.
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    GRAPHICAL POST PROCESSING TECHNIQUE FOR APPLIED SOFTWARE
    Wan Fang(Beijing Institute of Spacecraft Systems Engineering, Beijing 100086)
    1994, 14 (02):  . 
    Abstract ( 1406 )   Save
    aking the application program used in satellite design as an example this paper introdced how to do graphical processing of Fortran source code by means of mixed compilation of Fortran language,C language, X library and XView Toolkit'in sun workstation environment.
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