Table of Content

    25 August 2006, Volume 26 Issue 04 Previous Issue    Next Issue
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    Triple Difference-based Spacecraft GPS/INS Attitude Determination
    Yue Xiaokui Yuan Jianping(Northwestern Polytechnical University,Xi'an 710072)
    2006, 26 (04):  1-5+10. 
    Abstract ( 1680 )   Save
    Based on the triple difference carrier phase observables,a GPS/INS integration (algorithm) for attitude determination is studied.The proposed integration system also contains a(cycle) slip detection algorithm,in which inertial information is utilized to detect cycle slip.Some computer simulations are performed to verify the proposed integration system.The results show that accurate and reliable navigation solution can be gained.
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    Scanning Arithmetic for Soft-Landing Base on Time Optimizaion
    Geng Dianwu Song Zhengji Jiang Xingwei(Harbin Institute of Technology,Harbin 150001)
    2006, 26 (04):  6-10. 
    Abstract ( 1724 )   Save
    In order to reduce time used during the landing on the moon,the arithmetic to (simulate) human's logic is described.That can extract safe landing site based on the elevation map recognition.The high of the fraise,roughness and horizontal maneuvering distance are considered.The simulation shows that the method is practical and quite suitable for the lunar precision landing with hazard avoidance with a little time.
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    Global Navigation Constellation Design Based on Semi-analysis Method
    Shuai PingQu Guangji(China Academy of Space Technology,Beijing 100094)
    2006, 26 (04):  11-19. 
    Abstract ( 1815 )   Save
    The navigation constellation design is involved in the optimization issues of many(parameters).The goal of constellation design is to search a set of parameters and generate a(navigation) constellation using the ones.The constellation has not only the optimal performance,but also save the developing and maintaining cost of the satellite navigation system.Firstly,the(indexes) of evaluating constellation performance,algorithms of constellation availability and method of semi-analysis constellation design are presented as an important part.Secondly,the effects of the designed parameters on the constellation performance are analyzed and illustrated in detail,and(further) three global navigation constellation schemes given.Finally,by comparing and analyzing the performance indexes and positioning simulation results respectively based on three constellation schemes,it can be shown preliminarily that the semi-analysis method and constellation schemes are feasible.
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    Design and Control of Long-term Flyaround Trajectory for Target Spacecraft in Non-coplanar Elliptical Orbit
    Zhou Wenyong Yuan Jianping Luo Jianjun(Northwestern Polytechnical University,Xi'an 710072)
    2006, 26 (04):  20-25+31. 
    Abstract ( 1861 )   Save
    This paper is concerned with the design and guidance problems of a chaser satellite flyaround a target vehicle in non-coplanar elliptical orbit for a long time.At first,a(mathematical) model used to design a long-term flyaround trajectory is presented,which is(applicable) to the(situation) that a target spacecraft flies in an elliptical orbit.The conditions of the target at the center of the flyaround path are deduced.Considering the safety and task(requirement),a long-term(flyaround) trajectory is designed.Taking into account perturbations and navigation errors which can cause the trajectory unstable and mission impossible,a two-impulse control method is put forward.Some simulation works are carried out and the results indicate the flyaround mathematical model and the trajectory control method can be used in the design and control of a long-term flyaround trajectory.
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    Rapid Searching Method for Optimal Close Approach Orbit under Statistic Conditions
    Liu Luhua Zheng Wei Tang Guojian(College of Astronautical & Material Engineering,National University of Defense Technology,Changsha 410073)
    2006, 26 (04):  26-31. 
    Abstract ( 1607 )   Save
    The close approach analysis to surveilled satellites is necessary when designing a space surveillance satellite.Based on a simulation,a rapid optimal close approach orbit searching method is put forward.The simulation results approve the method is effective,and the statistic(parameters) are verified by the precise model.The creditability is validated either.
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    Symmetrical Refraction Design of Arched Fresnel Concentrator Lens
    Ma Mianjun Huang Liangfu Luo Chongtai Zhang Dejing(Lanzhou Institute of Physics,Lanzhou 730000)
    2006, 26 (04):  32-36. 
    Abstract ( 1783 )   Save
    On account that the mall prism has the biggest facial contour deformation tolerance corresponding the smallest deviation angle at different incident height of lens,basic principal for symmetrical refraction design of arched Fresnel concentrator lens is presented,and the(transmittance) and convergent property of transmitted light for symmetrical design and conventional design are compared.The facial contour deformation tolerance of Fresnel lens can generally arrive at 15~20 degree by this design method,and it's optical efficiency is higher than that of conventional designed Fresnel lens,Although there is off-focus phenomenon for the Fresnel lens designed by symmetrical refraction,transmitted light can still be focused on the sloar cells if the parameters are selected properly.
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    Factor of Leak Detection for Pressure Decay
    Yan Rongxin Liu Ping Feng Qi Hong Xiaopeng Shi Lixia(China Academy of Space Technology,Beijing 100094)
    2006, 26 (04):  37-41. 
    Abstract ( 2342 )   Save
    The principle of pressure decay leak detection and the error of leak detection are(introduced).The problems of pressure decay are investigated.The higher sensitivity can be obtained by increasing time of waiting and by choosing high accuracy thermometer and manometer.The(accuracy) of testing can be affected by water vapor pressure when environment temperature is lower than dew point temperature.The error of testing date can be decreased by measuring effective(volume) of weighing gas directly and meaning several test datum
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    Computation of System Temperature Error about Unite Surface Absorptivity
    Zhang Weiqing Xuan Yimin Han Yuge(School of Power Engineering,Nanjing University of Science andTechnology,Nanjing 210094)
    2006, 26 (04):  42-47. 
    Abstract ( 1751 )   Save
    Based on system sensitivity theory and system error analysis theory,by introducing the relation between radiation transfer coefficient and angle factor,a computational method,which computes system temperature error about unite surface's absorptivity is developed.Taking the(example) of radiation transfer among surfaces inside a cubic,system temperature error is computed by the computional method.It shows that system temperature sensitivity has higher precision,and experimental time influences on system statistical temperature error.If standard deviation is(smaller),ratio of system statistical temperature error is equal to ratio of system temperature(sensitivity).
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    Identification Method of Low Orbit Space Object Based on Narrow-band Radar
    Chen Wentong Liu Chaojun Zhang Hanhua Chen Zengping(National University of Defense Technology,Changsha 410073)
    2006, 26 (04):  48-54. 
    Abstract ( 1698 )   Save
    The low orbit space object's attitude movement's modulation to narrow-band echo(impulse) signal is analyzed.It shows that low orbit space object's narrowband signal's phase contains much more important features than its magnitude.Wavelet is applied to detect long-term evolution of the movement from the phase of narrow-band signal and to identify the low orbit space object's sketchy types.Experimentation with a great deal of real measured data proves that it be useful in(identifying) the low orbit space object's sketchy types.
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    Scheduling Algorithm to Balance the Space TT&C Network
    Zhai Zheng'an(China Satellite Launch Tracking and Control General,Beijing 100094)Tang Chaojing(National University of Defence Technology,Changsha 410073)
    2006, 26 (04):  55-60. 
    Abstract ( 1847 )   Save
    The central management and unified allocation mode applied to the space TT&C((telemetry),tracking and command) network,as well as the scheduling algorithms to meet multi-satellite TT&C missions are analyzed in the paper.A balanced scheduling algorithm is presented.Firstly,satellite TT&C missions are divided into different priorities and the TT&C stations are(allocated) according to the mission-oriented principal of optimization in order to support the(maximum) of missions as possible.Based on this result,re-optimization should be implemented to balance the workload of each station considering the workload and backup of TT&C stations.The presented scheduling algorithm takes account of success probability of satellite TT&C missions and makes the designated workload of each station more balanced than other algorithms.It is convenient for managing space TT&C network.
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    Design of Nitrogen Distributor and Application in a Simulator
    Zhou Jianhui Yang Chunxin Han Haiying Wang Ye(Beijing University of Aeronautics an Astronautics,Beijing 100083)Li Gao(Beijing Institute of Spacecraft Environment Engineering,Beijing 100029)
    2006, 26 (04):  61-66+71. 
    Abstract ( 1798 )   Save
    The Nitrogen distributor ventilating cooling method based on initial heat-exchange for cooling motion simulator is presented and designed.The flow fields and temperature fields of two methods in a simulator are simulated using computational fluid dynamics(CFD).The(simulation) results show that the Nitrogen Distributor cooling method is effective and can limit(maxtemperature) differences of Nitrogen within designing range,which afford a good piece of advice for microwave line.
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    Selection and Analysis of Manned Spaceflight Landing Site
    An Zhenhua(Beijing Institute of Tracking and Telecommunications Technology,Beijing 100094)
    2006, 26 (04):  67-71. 
    Abstract ( 1770 )   Save
    A selection,demonstration and comprehensive analysis of China manned spaceflight landing site are proposed based on the missions and characterisiics of manned spaceflight,and(considering) the requirements for the landing site.Its correctness and feasibility have been examined and verificd through many experiments of unmanned spaceflight and twice manned spaceflight.
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