卫星链路计算软件Satmaster帮助

上下行部分SiteName/LocationEntertheliteralnameofthesitewheretheearthstationislocateduptoamaximumof40characters(18forcountrydatafiles)Exampleinputforcountrydatafiles(18charactersmaximum)LiverpoolExampleinputforallotherforms(40charactersmaximum)Liverpool,Merseyside,England.基站名称输入基站所处位置的名称，最多40个字母。国家数据文件名举例（最多18个字母）：liverpool其他格式输入举例：Liverpool,Merseyside,England.SiteLatitudeEnterthelatitudeofthesitewheretheearthstationislocated.ThismustbeenteredindecimaldegreeswiththesuffixNfornorthandSforSouth.Nospacesareallowed.Examples53.33Nor27.89SImportantNote:Whenenteringdataintocountrydatafileslatitudesarerequiredindegreesandminutesformatasobtainedfrommapsandatlases.Inthiscasethefractionalpartrepresentsthenumberofminutesandcannotexceed59.Inallothercasesinputindecimaldegreesareassumed.Aconversionfacilityisprovidedunderthecalculatemenu.基站纬度输入地面站的纬度。必须以小数后跟N或S表示。不能输入空格。比如53.33N或27.89S注意事项当输入国家数据文件时纬度需要以地图上的度和分为单位。这种情况下，小数部分为分的表示，不能超过59。在其他情况下，都是以度来表示的。Caculate菜单中有一个转换工具。SiteLongitudeEnterthelongitudeofthesitewheretheearthstationislocated.ThismustbeenteredindecimaldegreeswiththesuffixWforwestandEforEast.Nospacesareallowed.Examples3.00Wor29.79EImportantNote:Whenenteringdataintocountrydatafileslongitudesarerequiredindegreesandminutesformatasobtainedfrommapsandatlases.Inthiscasethefractionalpartrepresentsthenumberofminutesandcannotexceed59.Inallothercasesinputindecimaldegreesareassumed.Aconversionfacilityisprovidedunderthecalculatemenu.基站经度输入基站的经度。必须以小数后跟E或W表示。不能输入空格。比如3.00W或29.79E注意事项当输入国家数据文件时纬度需要以地图上的度和分为单位。这种情况下，小数部分为分的表示，不能超过59。在其他情况下，都是以度来表示的。Caculate菜单中有一个转换工具。AltitudeofSiteEnterthealtitudeoftheearthstationabovesealevel.Thisisprimarilyusedinthecalculationofrainattenuationandatmosphericabsorption.Theunitsarekilometres.5.0kmisthemaximumaltitudeallowed.Enterzeroifyouwillpreferaslightlypessimisticworstcaselinkbudgetcalculation.基站海拔输入基站的海拔。这主要是用来计算雨衰和大气吸收值，单位是千米。最大允许输入的海拔为5km。如果需要比较悲观链路预算可以输入0。Frequency频率EnterthecentrefrequencyofthecarrierinGHz.Fortheuplink,typicalvaluesarearound6GHzand14GHzforCandKubandrespectively.Forthedownlink,valuesof4GHzand12GHzaretypical.Theacceptedrangeis1GHzto50GHz输入上行载波的中心频率，以Ghz为单位。典型C波段和Ku波段的值为6GHz和14GHz。下行的典型频率为4Ghz和12GHz。可输入的范围为1Ghz到50GHz。PolarizationThisissimplythepolarizationsystemadoptedbythewantedsatellitetransponderandiseitherlinear(ievertical&horizontal)orcircular.EntertheletterVforverticalpolarization,HforhorizontalpolarizationorCforcircularpolarization.极化这就是所需卫星转发器的极化方式，可以选线性（垂直和水平）或圆极化。输入“V”为垂直极化，“H”为水平极化，“C”为圆极化。SignalAvailabilityDependingonyoursystemdesignrequirementsachoiceofsignalavailabilityshouldbespecified.FortypicaldomesticsatelliteTVsystems,afigureof99.5%availabilityisnormallysufficient.Infactmostpackagedfixeddishsystemsaredesignedaroundthisfigure.ForSMATVyoumayrequireahigherfigureof99.9%andcableheadevenhigher.Theupperlimitprovidedis99.999%butthislevelofperformanceisrarelynecessaryorevenachievable.Theparameterisusedincalculatinganappropriatefademarginbasedontherain-ratestatisticsforthesite.IfyouliketoworkwithworstmonthstatisticsaconversiontoaverageyearsignalavailabilityisprovidedundertheCalculatemenu.Withlinkbudgetsusinguplinkpowercontrolsystemsahigheravailabilityisoftenspecifiedfortheuplinkthanthedownlink.信号可用度（年平均）根据你的系统设计需求，信号可用度应该是确定的。典型的国内TV系统，这个数到99.5%为宜。实际上大多集成的碟形天线系统按照这个数字设计。SMATV（卫星公共接收电视）需要高到99.9%的可用度，电视终端机则更高。最高可以设为99.999%但是这种程度的可用度不常用也不可行。这个数值经常用来计算合适的雨衰。如果你愿意通过“worstmonth最糟糕的一个月”数值转换为年平均信号可用度，可以通过Calculatec菜单下的工具进行换算。如果链路使用上行功率控制系统，经常要设置一个较高的系统可用度。AntennaApertureAntennaapertureisnormallytakenastheoveralldiameterofaparabolicdish,themajordimensionifanoffsetfocusantenna.Unitsarealwaysmetric(inmetres)toconformtointernationalengineeringpractice.Thelowerlimithandledis0.2metresandthehighest50metres.天线口径通常是抛物线天线的直径，偏馈天线的主要直径。单位都是米。最少为0.2米，最大为50米。AntennaEfficiencyAntennaefficiencyistheamountofincidentsignalactuallycollectedbythedishandfeed,expressedasapercentage.Qualityofconstruction,signalblockagebyheadunits,andmethodoffeedaffectsthisparameter.Mostantennashaveefficienciesofbetween60%and70%.Ifyoudonotknowtheefficiencyoftheantennathenenter60%asaworstcasevalue.Withlinkbudgetanddualfeedforms,thevalueenteredmaybeprefixedwitha+charactersothevaluewillbeinterpretedasagain,indBi,ratherthanefficiency.天线效率天线效率就是入射信号呗反射面和馈源收集到得数量，表示为一个百分比。建设施工质量，前馈部分的遮挡还有馈源材料会影响这项参数。多数天线的效率在60-70%之间。如果你不知道则输入60%作为最悲观估计在链路预算和双馈形式中，这个值必须加一个“+”前缀以便程序将其解读为增益，以dBi为单位，而不是天线效率。CouplinglossThisparameteristhetotallossduetotheinsertionofwaveguidecomponentsandpolarizers.ValuesareexpectedindBandaretypicallyintheorderof0.3dB.Youshouldaddalltheinsertionlossesofwaveguidecomponents,suchasOMTsandpolarizers,thatyouintendtouse.耦合衰减这个数值是波导原件、偏振器引起的一切衰减。单位是dB，典型值为0.3dB。你应该输入整体的波导元器件的衰减，如OMT和偏振器。AntennamisspointinglossThisparameterallowsforthepointinglossbetweenthegroundstationantennaandthesatelliteantenna.Itisunlikelyinpracticethattheantennawillbetargetedexactlyduetoinitialinstallationerrors,factorssuchasthestabilityduetowindandthestationkeepingaccuracyofthesatellite.Alargeantenna,havinganarrowbeamwidthandbeingrelativelyunsta