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Table of Content

    25 October 1995, Volume 15 Issue 05 Previous Issue    Next Issue
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    A NEW TECHNOLOGY OF REMOTESENSING IMAGE COMPRESS
    Yu Tao; Ju Dehang; Wu Ji(Xi'an Institute of Space Radio Tech, Xi'an 710000)
    1995, 15 (05):  . 
    Abstract ( 1601 )   Save
    This paper proposes a new technology of remote sensing data compression based on biorthogonal wavelet bases. The linear phase and symmetric exact reconstruction wavelet FIR fliters are designed. Finally, a good rebuilt remote sensingimage compressed by wavelet FIR filters is obtained.
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    A GENETIC OPTIMIZATION BLOCK MATCHINGALGORITHM FOR IMAGE SEQUENCE CODING
    Tan Xijing ;Ping Xijian(Information Engineering Institute of PLA, Zhengzhou 450002)
    1995, 15 (05):  . 
    Abstract ( 1566 )   Save
    In this paper discuss an algorithm of the motion estimation in sequenceimage coding. After analysing traditional Block Matching Algorithms (BMA), an improved hierarchical search algorithm, which adopts the idea of generic optimization algorithm and alleviates the local minimum problem, is presented. Theoretical analysisand computer simulation show that a higher compression rate than those of existingfast-search algorithms is obtained and the computation time compared with full searchalgorithm is also reduced.
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    A DIAGNOSTIC SYSTEM BASED ONFAULT TREE MODEL
    Ji Changwei;Du Yuanhu; Rong Jili; Huang Wenhu(Harbin Institute of Technology, Harbin 150001 )
    1995, 15 (05):  . 
    Abstract ( 1765 )   Save
    The paper presents a diagnosis method based on fault tree model andrealizes a diagnostic system. First, a hierarchical diagnosis model is presented and acertain reasoning strategy and a possible reasoning strateyg are proposed. Secondly, afault tree-objected and frame and generalized rule based hybrid knowledge representation method is presented. Finally, the diagnostic system is realized in BORLANDC+ +, using COMPAQ 486 with WINDOWS operating platform, and demonstrated bydiagnosing a circuit testbed.
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    ON PROGRESS OF CHINESERECOVERABLE SATELLITES
    Wang Xiji(Chinese Academy of Space Technology, Beijing 100081 )
    1995, 15 (05):  . 
    Abstract ( 1745 )   Save
    From 1975 to 1994 China has developed three types of recoverablesatellites, they are FSW-0, FSW-1 and FSW-2 satellites. China has launched 9 FSW-0, 5FSW-1 and 2 FSW-2 satellites. Among the 16 launched satellites, 15 of themwere successfully recovered. As the development works progressing, the satellitemass increases from FSW-0's 1790kg to FSW-2's 2760kg, and the operating lifetimeprolongs from FSW-1's 3days to FSW-2's 16 days. The the Chinese recoverable satellites are multifuction satellites
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    STUDIES ON NOVEL ENERGY STORAGE MATERIALSAND THEIR APPLICATION PROSPECT
    Chen Chuanfu; Xi Fu ;Pan Zenfu; Zhang Cen(Institute of Chemistry, Academia (Beijing Institute of Spacecraft SystemsSinica, Beijing 100080) Engineering, Beijing 100086)
    1995, 15 (05):  . 
    Abstract ( 1774 )   Save
    Two kinds of solid-solid phase change materials, which are organoammonium metallic compounds and polyalcohol compounds (plastic crystals), arestudied. Epoxy resin and silicon rubber are adopted to blend with solid-solid phasechange materials in casting. Their thermal properties are characterized by differentialscanning calorimetry (DSC) and the results show that some solid-solid phase changematerial systems with phase transition temperature range of 30-40℃, transition enthalpy about 100J/g have been obtained. The application prospects for energy resources, spacecraft, agriculture, constructions, chemical industry and metallurgyetc. have been discussed.
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    A REVIEW OF MULTIBEAM SATELLITE ANTENNAS
    Xie Chongjin; Wang Huazhi(Beijing University of Posts and Telecommunications, Beijing 100088)
    1995, 15 (05):  . 
    Abstract ( 2307 )   Save
    The need to constantly increase the capacity and efficiency of communication satellites has led to the advent and development of multibeam satellite antenna technology. In this paper, four major types of multibeam satellite antennas are reviewed: single offset reflector with feed array, shaped reflector system, active arraysand imaging reflector antenna. The review includes their structure, analytic methodand applied area. Examples of existing systems are also given.
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    DEVELOPMENT OF PCM DIGITAL AUDIODECODER FOR DBS RECEIVER
    Yu Yucai(Beijing Institute of Satellite Information Engineering, Beijing 100074)
    1995, 15 (05):  . 
    Abstract ( 1707 )   Save
    The PCM Digital Audio for DBS television is studied in this paper.Basing on the characteristics of receiving DBS television in China, developed a smallPCM digital audio decoder. The decoder in combination with the C-band satellite receiver can replace an imported Ku-band receiver, and has potential social profit and econmical value.The decorder is tested by Satellite Earth Station Test Center, and the resultsshow that the decoder's high quality audio is as good as that of imported Ku-band receiver.
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    HEATING TEST AND NUMERICAL CALCULATIONON HONEYCOMBED PLATE
    Qie Dianfu; Dai Sihong; Guo Xiucai; Liu Feng(Beijing Institute of Satellite Environment Engineering, Beijing 100029)
    1995, 15 (05):  . 
    Abstract ( 1641 )   Save
    An areodynamic heating simulation test method on a honeycomb platesurface and its numerical calculation method to derive the temperature distributionwith time and the thermal conductivity are discussed. It's a challenge to make the testand calculate the thermal conductivity because of the simulated heat flux varying process so quickly with time as well as its complicated structure. An more exact heat fluxsimualtion test method and numerical treatment method are presented here.
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    TYPICAL RESULTS AND ANALYSEFOR HF BACKSCATTER OBSERVATION
    Li Yuhui(China Research Institute of Radio Wave Propagation, Xinxiang 453003)
    1995, 15 (05):  . 
    Abstract ( 1814 )   Save
    HF backscatter observation experiment were performed from Octoberto December, 1993 in Xinxiang and some significant results of)tained. The experimental results show: 1. Type and morphological characteristic of HF backscatter ionogram. 2. Maximum observed frequency in HF backscatter ionogram and day variblelaw of slope distance. 3. Es succession variation course and characteristics found outduring HF backscatter observation.
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