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    25 April 2016, Volume 36 Issue 2 Previous Issue    Next Issue
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    InvestigationoflightconcentratingmodeforSSPS
    ZHANG Xing-Hua, HOU Xin-Bin, WANG Li, YAN Yong
    2016, 36 (2):  1.  doi: 10.16708/j.cnki.1000-758X.2016.0019
    Abstract ( 705 )   PDF (5018KB) ( 1093 )   Save
    Spacesolarpowerstation(SSPS)isaspacesystemcollectingandtransformingsolarenergyintomicrowaveorlaserintheorbitandwirelesslytransmittingthepowertothegroundstation,wherethepowerischangedintoelectricity.Solarconcentrationisamethodofcollectingspacesolarenergy,andisappliedto  manySSPSconcepts.AfterreviewingtheprogressofthesolarconcentratingSSPS,andsummarizingtheconceptsandtechnologiesofsolarconcentrationrelatedtotheSSPS,thesolarconcentrationisdividedintofourmodescorrespondingtothreelevels,andboththeadvantagesanddisadvantagesofeachmodewereanalyzed.ThedevelopmentofthesolarconcentratingSSPSwasproposed.
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    Anamplitudephasemeasurementmethodforbeamformingnetworkwithnonorthogonalcodes
    GAO Yuan, AN Jian-Ping, ZHOU Hui, HAO Shi-Guang, CHAI Yuan
    2016, 36 (2):  13.  doi: 10.16708/j.cnki.1000-758X.2016.0021
    Abstract ( 705 )   PDF (1894KB) ( 661 )   Save
    Theapplicationofanamplitudeandphasemeasurementsystembasedonthespreadingcodesislimitedbytherequirementsofcodeorthogonality.Anamplitudephasemeasurementmethodfordigitalbeamformingnetworkbasedonnonorthogonalcodeswasproposedtoovercomethelimitation.Themainsourceoferrorsinthemeasurementsystemwithnonorthogonalcodeswasmultipleaccessinterference(MAI).Therefore,decorrelatingalgorithmwasproposedtosuppresstheMAIatthecostofincreasingthenoiseslightly.Theoreticalanalysisprovidedthetheorylowerboundoftheamplitudeandphasemeasurementandtheeffectofthesystemerrorandmutualcouplingonthemeasurementaccuracy.Simulationresultsdemonstratethattheaccuracyofthemeasurementsystemwithoutdecorrelatingalgorithmisunacceptable.However,theproposedmethodcansatisfytheaccuracyrequirementsof±01dBand±1degreeundertheconditionsthattheinbandsignaltonoiseratio(SNR)ishigherthan10dB.Moreover,thesimulationresultsareingoodagreementwiththoseoftheoreticalanalysis.
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    SimulationandresearchonRAIMalgorithmbuiltincivilaviationairbornereceiverbasedonBeiDousatellitesystems
    LIU Rui-Hua, DENG Ming-Zhi, WEI Bao-Guo, XING Zhao-Dong
    2016, 36 (2):  20.  doi: 10.16708/j.cnki.1000-758X.2016.0022
    Abstract ( 699 )   PDF (4379KB) ( 806 )   Save
    Receiverautonomousintegritymonitoring(RAIM)algorithmisalreadymatureintheory.ButastoBeiDounavigationsatellitesystem(BDS),thereisrareanalysisabouttheperformanceofRAIMwiththeobserveddata.AccordingtotheconstellationstatusofBDSsystemandtheperformanceofopenservice,basedontherequirementofnonprecisionapproachincivilaviationfield,thesimulationandresearchonRAIMwerepresented.Firstly,theavailabilityofRAIMinAsiaPacificwascalculated.Then,thefunctionandcapabilityoffailuredetectionandidentificationwiththeobserveddatafromNovAtelreceiverwereanalyzedindifferentscenesandfaulttypes.Thesimulationresultsshowthattheaverageofvisiblesatelliteismorethan7,andtheHPLvaluesarelessthan500meters.Furthermore,themeasuredresearchshowsthattheRAIMcandetecttheanomalypseudorange.Thatistosay,BDSsystemmettheneedsoftheRAIM.TheconclusionisthattheBDSissuitableforRAIM,andcanprovidetherequirednavigationperformance(RNP)fornonprecisionapproach(NPA)inthecivilaviationfield.
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    Worstcaseresponsetimeanalysisofmultilevelinterruptsystems
    YU Guang-Liang, YANG Meng-Fei, XU Jian, JIANG Hong
    2016, 36 (2):  28.  doi: 10.16708/j.cnki.1000-758X.2016.0003
    Abstract ( 754 )   PDF (1101KB) ( 688 )   Save
    Acomputationmodelintegratedwithinterruptsandtaskswaspresentedfortheanalysisofworstcaseresponsetime(WCRT)foranaerospaceembeddedsystemwithmultilevelinterrupts.Bothinterruptsandtaskswasusedforaunifiedprioritydefinitioninthismodel,sothetiminganalysisofnestedinterruptscanbecombinedwithtaskresponsetimeanalysistechniques.TheWCRTofbothinterruptsandtaskswasderivedintheintegratedmodel.Furthermore,detaileddescriptionsofkeyparameterswereproposedandthedifferencesbetweeninterruptsandtaskswerealsodiscussed.TheopensourceLEON3processorplatformandModelsimsoftwarewereintroducedtosimulateandverifythemethod.TheresultsshowthattheoverestimateoftaskWCRTislessthan5%whichdemonstratestheeffectivenessofthemethodandthevalueforengineeringapplications.
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    HighprecisionmicronanosatelliteformationkeepingbasedonSiCMEMSmicrothrusterarray
    FAN Lin-Dong, YANG Bo, MIAO Jun, LONG Jun, LIU Xu-Hui
    2016, 36 (2):  37.  doi: 10.16708/j.cnki.1000-758X.2016.0002
    Abstract ( 653 )   PDF (1803KB) ( 846 )   Save
    Withthedevelopmentofthemicro/nanosatellites,theproblemofthestationcontrolneedstobesolved.Thetraditionalpropulsiontechnologycan′tmeettherequirementsofhighprecision.Therefore,theSiCMEMSMicrothrusterarraywasproposedfortheformationkeepingofthemicro/nanosatellites.Consideringthedifferentcharacteristicsofthearrayfromthetraditionalthruster,theinputandoutputmodelwasestablishedandtheinstantaneouspulsecontrolstrategywaspresentedtokeeptheformation.Thesimulationresultsshowthatthearraycanbeappliedtotheneardistanceformationofmicro/nanosatellites,andithasahighpositionaccuracyof3mm.Inaddition,thethrusters′consumptionandcontrolprecisioninfluencedbythesinglethrusterchargeandcontrollerparameterswereanalyzed.Whentheimpulseofthesinglethrusterrangeis8×10-6~20×10-6N·s,itcangetgoodcontrol.
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    Directcouplingmatrixsynthesistechniqueforfilterswithnonresonatingnodes
    LIU Hao, LI Sheng-Xian
    2016, 36 (2):  46.  doi: 10.16708/j.cnki.1000-758X.2016.0023
    Abstract ( 667 )   PDF (1537KB) ( 1568 )   Save
    Animproveddirectcouplingmatrixsynthesistechniquewaspresentedbasedonthetheoryofnonresonatingnodes.Bytreatingnonresonatingnodesasresonatingnodes,thecouplingmatrixwasobtainedusingthecanonicalsynthesis.Thensimilartransformwasconductedto  thematrixsothattheelementscorrespondingtothelocationofnonresonatingnodescontainnoinformationontransmissionzeros.〖JP2〗Andproportionaltransformwasconductedtotherowsandcolumnsoftheelements,sothefilternetworkincludednonresonatingnodesagain.Thenthematrixwhichmaybeusedtodesignthefilterswithnonresonatingnodeswasobtained.Themethodsimplifiesthesynthesis,reconfigurationandsimulationoffilterswithnonresonatingnodes.SimulationresultsinMATLABandHFSSprovethesynthesistechniquereasonableandfeasible.
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    Anewdefinitionevaluationmethodforremotesensingimagesofsatellite
    TAN Wei, YANG Bing-Xin, HE Hong-Yan
    2016, 36 (2):  50.  doi: 10.16708/j.cnki.1000-758X.2016.0024
    Abstract ( 655 )   PDF (5017KB) ( 1772 )   Save
    Anewevaluationfunctiontocomputeremotesensingimagedefinitionwasproposedaccordingtoengineeringapplicationsandfeaturesofremotesensingimage,toovercometheshortagesoftraditionalimagedefinitionevaluationfunctions.Forlargedataanddifferentscenerydensityanddistributionofremotesensingimages,thedefinitionevaluatingprocesswasseparatedastargetareadetectionandcharacteristicparameterextraction.Firstly,detectionfunctiondetectedwholeimagetogettherichsceneryandobviousedgeareaastargetarea.Thenagraygradientfunctionmadeimagegraypretreatmentandextracteddefinitioncharacteristicparameterstoevaluateimagedefinition.Threedifferentkindsofremotesensingimages,namely,emulateddefocusingimage,emulatednoiseimageandonorbitsatelliteimagewereusedintheproposedmethod,toverifyitseffectivenessandaccuratenessbycomparingitwithfourtraditionalmethods.Theanalysisandemulationresultsshowthattheproposedmethodcanmeetthefourbasicdemandstoevaluatingremotesensingimagedefinitionandtacklethedeficienciesoftraditionalfunctionsinevaluatingdifferentremotesensingimages,itisavailabletoevaluateremotesensingimagedefinition.
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    Thermaldesignandonorbitthermalanalysison YuTu rovermovablecameras
    ZHANG Bing-Qiang, XIANG Yan-Chao, CHEN Jian-Xin, SONG Xin, MA Ju-Yin
    2016, 36 (2):  58.  doi: 10.16708/j.cnki.1000-758X.2016.0001
    Abstract ( 546 )   PDF (1849KB) ( 421 )   Save
    InthebrutaltemperatureenvironmentinSinusIridiumwiththerangebetween-180℃to+90℃,itneedstosolvecameraheatdissipationduringlunardaytimeandheatpreservationinmoonlitnightwithoutelectricenergysupplyunderthecomplexrotationof YuTu Rovermast.Besides,theuncertaintyoflunarduststillresultsinriskstothermaldesign.Inordertosolvetheextremehightemperatureproblemindaytime,themastrotatestoanoptimalpositionforheatdissipationandavoidsthecamerabeingtoohot,andtheproportionofpoweronandoffisoptimized.Inextremelylowtemperatureatnight,thethermalcouplingstateofthecameraandtheroverhasbeenchanged;themastisfoldedintothefencetokeepwarmbymeansofheatpreservationsystems.Basedontheanalysisofthecauseofdustsubsidence,themaxsunelevationangleforworkingisrestrictedtoavoidrisksbydust.Accordingtothethermalanalysisresultsandinorbitresults,itcanbeconfirmedthatthehighesttemperaturedecreased15degreesbymethodsoffindingoptimalpositionandoptimizingtheproportionofpoweronandoff.Byfoldingthemastinmoonnight,camerashavesafelyundergonethecoldnight,therefore45WpowergeneratedbyRHUhasbeensaved.Itindicatesthatthecouplingmethodbetweenthermalcontrolandpostureadjustmentcanbeusedtosolvethehighlowtemperatureproblemofmovablecamerasontheplanet′surfacerover,andreducetheroverpowerdemandforRHU.Itcouldprovidethermaldesignreferenceforthefollowoncelestialbodysurfaceexplorations.
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    Aninstallationdesignofimprovingpointingaccuracyofstarsensorbasedonsemirigidconnection
    ZHU Hua, ZHANG Chun-Yu, ZHOU Xu-Bin, ZHANG Zong-Hua, GU Zhi-Yue, LYU Kai
    2016, 36 (2):  66.  doi: 10.16708/j.cnki.1000-758X.2016.0025
    Abstract ( 705 )   PDF (5994KB) ( 712 )   Save
    Satelliteperformanceinorbitisimpactedbypointingaccuracyofstarsensorandsyntheticapertureradar(SAR)middleplatebecauseofthermaldeformation.CharacteristicsaboutthermaldeformationofstarsensorandSARwerestudiedandanalysed,andinstallationbetweenSARandsatellitebodywasdesigned.Takingonesatelliteasanexample,SARandsatellitebodywereconnectedwithasemirigid(horizontalconstraintreleased)method,andtheinfluenceofsatellitethermaldeformationwasisolatedtoSARwithacertainrigidity.Asaresult,pointingaccuracyofstarsensorrelativeSARmiddleplateincreased,andmettherequirementofsatelliteimaging.Thisisverifiedbycalculationanalysisandtest,andcanprovidereferenceforotheraerospaceelectroncequipments.
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    Effectofdivergingvariablecrosssectionchannelonperformanceofacuspedfieldthruster
    CHEN Peng-Bo, LIU Hui, HU Peng, SUN Qiang-Qiang, YU Da-Ren
    2016, 36 (2):  74.  doi: 10.16708/j.cnki.1000-758X.2016.0026
    Abstract ( 769 )   PDF (8606KB) ( 357 )   Save
    Theadaptabilityofcuspedfieldthrusterchangeswithdifferentoperatingconditions,especiallywithdifferentefficiencies,whichchangesalotatdifferentgasflowrates.Toovercomethisproblem,adivergingvariablecrosssectionchannelwasproposedtoimprovetheperformanceofcuspedfieldthrustersatlowandmiddlegasflowrate.Meanwhile,twoconstantsectionchannelswithabigdiameteranda  smalldiameterrespectivelywereintroducedtobecomparedwiththedivergingchannel.Althoughthedivergingchannelmaycausealittledeclineintheatomdensitycomparedtothesmall  constantsectionchannel,thedivergingchannelimprovestheefficiencyatbothlowandmiddlegasflowratesonthepremiseofprovidingaconsiderablethrust,becauseitdecreasestheenergylossofionsatexitandpromotesionizationbyimprovingthemagneticmirrorratio.Incomparison,boththebigconstantsectionchannelandthesmallconstantsectionchannelhavelowperformancesduetoalowerdensityofgasandabiggerwallloss.Therefore,adivergingchannelisbeneficialtoimprovingtheperformanceofacuspedfieldthrusteratlowandmiddlegasflowrate.
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    StudyonEMLandPIMfromconnectiongapinahighpowercoaxialresonator
    YU Xu-Min, TANG Xiao-Hong, WANG Juan, DAI Feng, LIN Hua-Jie
    2016, 36 (2):  81.  doi: 10.16708/j.cnki.1000-758X.2016.0027
    Abstract ( 698 )   PDF (1213KB) ( 776 )   Save
    Underthevacuumandhighpowercondition,anunstableslightgapofconnectingstructureofacoaxialresonatorwillhaveseveralrisks,includingPIM(PassiveInterModulation)andEML(ElectroMagneticLeakage)problems.Thepercentageofgap′sintegralofsurfacecurrentinthewholeresonatorcavitywasanalyzed.Itshowsthatthegap′slocationisfartherawayfromhighsurfacecurrentstrengthpartofthecavity,thepercentageissmaller.Threekindsofcoaxialresonatorshavebeensimulated.Astableonewaspresentedforreducingthoserisks.Theconnectiongapofthecoaxialresonatorisfarawayfromelectricfieldwavenodesavailable.
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