测绘工程专业英语全文翻译

./Uuit1WhatisGeomatics?〔什么是测绘学GeomaticsDefined〔测绘学定义WheredoesthewordGeomaticscomefrom?〔Geomatics－测绘或地球空间信息学,这个名词是怎么来的呢？GEODESY+GEOINFORMATICS=GEOMATICSorGEO-forearthand–MATICSformathematicalorGEO-forGeoscienceand-MATICSforinformatics.〔大地测量学＋地理信息学＝GEOMATICS测绘学或者geo代表地球,matics代表数学,或者geo代表地球科学,matics代表信息学Ithasbeensaidthatgeomaticsismanythingstomanypeople.〔据说测绘学这个词对不同的人有不同的理解ThetermgeomaticsemergedfirstinCanadaandasanacademicdiscipline;ithasbeenintroducedworldwideinanumberofinstitutesofhighereducationduringthepastfewyears,mostlybyrenamingwhatwaspreviouslycalled"geodesy"or"surveying",andbyaddinganumberofcomputerscience-and/orGIS-orientedcourses.〔这个术语[term术语]作为一个学科[academicdiscipline学科]第一次形成[emerge]于加拿大；在过去的几年里被全世界的许多高等教育研究机构所熟知,通常是以前的"大地测量学"或"测量学"在引入了许多计算机科学和GIS方向[或"基于GIS"]的课程后重新命名的。Nowthetermincludesthetraditionalsurveyingdefinitionalongwithsurveyingsteadilyincreasedimportancewiththedevelopmentofnewtechnologiesandthegrowingdemandforavarietyofspatiallyrelatedtypesofinformation,particularlyinmeasuringandmonitoringourenvironment.〔随着新技术的发展和不断增长的对空间关系的信息类型的需求,尤其是在测量和监测我们的环境方面[环境监测],现在,传统测量学定义连同[alongwith]日益[steadily稳定的]增长的测量的重要性一起包含在这个术语里了。[逗号后面的句子修饰demand]Increasinglycriticalareareasofexpandingpopulations,appreciatinglandvalues,dwindlingnaturalresources,andthecontinuingstressingofthequalityofourland,waterandairfromhumanactivities.〔日益增长的危机来自人口扩张,地价上涨,资源紧缩[紧张],还有由于人类活动引起的土地、水、空气质量的持续的压力[由人类活动带来的土地、水、空气质量的恶化]Assuch,geomaticsbridgeswidearcsfromthegeosciencesthroughvariousengineeringsciencesandcomputersciencestospatialplanning,landdevelopmentandtheenvironmentalsciences.〔这样,测绘学在地球科学,各种工程学[engineeringsciences工程学],计算机科学,空间规划,土地开发和环境科学相互之间架起了广泛的桥梁。NowthewordgeomaticshasbeenadoptedbyseveralinternationalbodiesincludingtheInternationalStandardsOrganization<ISO>,soitisheretostay.〔现在geomatics这个词已经被包括ISO[国际标准化组织]在内的数个国际机构[internationalbodies]所采用,因此它就这样被普遍接受[beheretostay习惯用语"被普遍接受"]Theterm"surveyor"istraditionallyusedtocollectivelydescribethoseengagedintheaboveactivities.〔surveyor这个词按惯例用来总指〔这换成"总称"较好[collectively全体的]那些从事上述活动的人。MoreexplicitjobdescriptionssuchasLandSurveyor,EngineeringSurveyororHydrographicSurveyorforexample,arecommonlyusedbypractitionerstomoreclearlydescribeandmarkettheirspecializedexpertise.〔更具体的[explicit清楚的、直接的]工作如土地测量员、工程测量员和水道测量员,一般[commonly一般地]被业内人士[practitioners从业者]用来更准确的描述他们的专门技术。[直译为：更清楚的工作描述就如如土地测量员、工程测量员和水道测量员,一般被从业者用来更准确的描述他们的专门技术。]Thetermgeomaticsisarecentcreationtoconveythetruecollectiveandscientificnatureoftheserelatedactivitiesandhastheflexibilitytoallowfortheincorporationoffuturetechnologicaldevelopmentsinthesefields.〔geomatics这个术语是个新词,表达[convey传达]了实体集合和它们相关联[related]的活动的自然科学,并使这些领域的未来技术发展的结合[incorporation结合]成为可能。[flexibility弹性、机动性]Adoptionofthetermalsoallowsacoherentmarketingoftheprofessiontoindustryandschoolsonaworldwidebasis.〔这个术语的采用同时也在全世界范围里为行业[industry]里和学校建立了[allow允许了]一个一致的[coherent]专业市场Asaresult,bothcourseandawardtitlesinthetraditionalLandSurveyingsectoratmanyoftheworld’sleadinguniversitiesarebeingchangedto"DegreeinGeomatics".〔结果,世界上许多一流大学的传统的测量专业[部门]的无论是课程还是授予资[授予学位名称]格都改为"测绘学位"[DegreeinGeomatics]的了Thisdoesnotsuggestthedemiseoftheterm"surveyor"andgraduateswillstillpracticeaslandsurveyorsorphotogammertrists,etc.asappropriatetotheirspecialization.〔这并不意味着"surveyor"这个词的消亡,测绘毕业生还将从事适合他们专业的[asappropriatetotheirspecialization]土地测量员、摄影测量员及其他[ect.]的工作Inthelastdecade,therehasbeendramaticdevelopmentandgrowthintheuseofhardwareandsoftwaresolutionstobothmeasureandprocessgeo-spatialdata.〔在过去的十年中,在应用硬件和软件的方法[solution解决方法]来测量和处理地球空间数据工作时有着戏剧性的发展和增长[intheuseof在使用……时]Thishascreatedandwillcontinuetocreatenewareasofapplication,withassociatedjobopportunitiesforsuitablyqualifiedgraduates.〔创造并将继续创造新的应用[application]领域,并为合适的、合格[qualified有资格的]的毕业生提供相关的[associated]工作。Asaresult,theroleofthe"surveyor"isexpandingbeyondtraditionalareasofpractice,asdescribedabove,intonewareasofopportunity.〔结果是,"surveyor"的角色大大超越传统实践领域――如前面所述的领域,进入到新的[opportunity机会、时机]的领域。Inaddition,recentadvancesinthetechnologyofdatacollectionandprocessinghaveblurredtheboundariesofpracticeandactivitybetweenwhatwerepreviouslyregardedasrelatedbutseparateareas.〔另外,最近的数据采集和处理技术的发展模糊了以前被认为有联系却分离的领域的[实践的活动的practiceandactivity]界限Suchdevelopmentsareforecasttocontinueandwillcreatenewcareerpathsforgraduateswhoseeducationandtrainingisbroadlybasedandofahighacademicstandard.〔可以预见[forecast],这种发展继续并将为涉猎广泛、学识一流的[broadlybasedandofahighacademicstandard]毕业生创造新的事业。Toenablegraduatestotakefulladvantageofthesedevelopments,significantchangesineducationandtrainingarerequired.〔为了使毕业生能充分利用[takefulladvantageof]这些发展,教育和训练的重大改革[significantchanges]成为必需的Academicandprofessionalinstitutionsarealsoresponding,inpart,byadoptingthetermgeomaticsbothasacourseandasanawardtitle.〔学院的和专业的机构也作出反应,部分地,采用术语"geomatics"作为一门课程和一项授予资格[授予学位名称]。Aworkingdefinitionofgeomatics,whichreflectscurrentthinkingandpredictedchange,is:〔测绘学的一个现在使用的反映了当前的思想和对未来的预期的定义是：Thescienceandtechnologyofacquiring,storing,processing,managing,analyzingandpresentinggeographicallyreferencedinformation<geo-spatialdata>.〔获取、处理、存储,分析和上呈[presenting呈现]地理参考信息〔地理空间信息的科学和技术。Thisbroadtermappliesbothtoscienceandtechnology,andmapping,geodesy,satellitepositioning,photogrammetry,remotesensing,geographicinformationsystems<GIS>,landmanagement,computersystems,environmentalvisualizationandcomputergraphics.〔这个广泛的术语应用于科学和技术,以及制图、大地测量学、卫星定位、摄影测量学、遥感、地理信息系统、土地管理、计算机系统、环境可视化和计算机制图等领域Severaltermssuchas"geomatics","geomaticengineering,"and"geoinformatics"arenowincommonusepertainingtoactivitiesgenerallyconcernedwithgeographicinformation.〔现在一些术语如"测绘学","测绘工程"和"地学信息学"共同应用于某些活动中―――专属于[pertainto]通常[generally]涉及[concernwith]地理信息的活动。Thesetermshavebeenadoptedprimarilytorepresentthegeneralapproachthatgeographicinformationiscollected,managed,andapplied.〔这些术语起初被采用用来表示地理信息的采集、管理和应用的总体的方法。Alongwithlandsurveying,photogrammetry,remotesensing,andcartography,GISisanimportantcomponentofgeomatics.〔连同土地测量学,摄影测量学,遥感和制图学一起,GIS也是测绘学中重要的一个组成部分。BranchesofGeomatics〔测绘学分支Dataacquisitiontechniquesincludefieldsurveying,globalpositioningsystem<GPS>,satellitepositioning,andremotelysensedimageryobtainedthroughaerialphotographyandsatelliteimagery.〔数据获取技术包括普通野外测量,GPS测量,卫星定位和遥感图像获取,通过航空摄影和卫星成像Italsoincludestheacquisitionofdatabasematerialscannedfromoldermapsandplansanddatacollectedbyrelatedagencies.〔它还包括数据库资料的获取――通过扫描就有地图和设计图,还有有关机构收集的数据。Datamanagementandprocessarehandledthroughtheuseofcomputerprogramsforengineeringdesign,digitalphotogrammetry,imageanalysis,relationaldatabasemanagement,andgeographicinformationsystems<GIS>.〔通过计算机程序,数据管理和处理应用于工程设计,数字摄影测量[digitalphotogrammetry],图像分析,相关资料库的管理和GIS。Dataplotting<presentation>ishandledthroughtheuseofmappingandotherillustrativecomputerprograms;thepresentationsaredisplayedoncomputerscreens<whereinteractiveeditingcanoccur>andareoutputonpaperfromdigitalplottingdevices.〔数据成图[数字成图]是通过制图和其他直观的计算机程序[illustrative直观的、说明性的]进行的；其表达显示在计算机屏幕上〔交互式编辑处理,也可以通过数字绘图仪输出到纸上。[handle操作、处理]Oncethepositionsandattributesofgeographicentitieshavebeendigitizedandstoredincomputermemory,theyareavailableforusebyawidevarietyofusers.〔一旦地理实体的位置和属性被数字化并被存储进计算机存储器,就可以有效的[available有效的、可用的]为广泛的各种的使用者所用Throughtheuseofmoderninformationtechnology<IT>,geomaticsbringstogetherprofessionalsinthefollowingdisciplines:surveying,mapping,remotesensing,landregistration,civilandmarineengineering,forestry,agriculture,planninganddevelopment,geology,geographicalsciences,infrastructuremanagement,navigation,environmentalandnaturalresourcesmonitoring,andcomputerscience.〔通过现代[估计moderm应该是modern]信息技术,测绘学将以下学科的专业人员整合到一起：测量学、制图学、遥感、国土注册、土木[civil民用的]工程和海洋工程,林业,农业,决策与发展,地质学,地理科学,基础设施[infrastructure]管理,导航,环境与自然资源监测和计算机科学。OtherDefinitionsofGeomatics〔测绘学的其他定义AsdefinedbytheCanadianInstituteofGeomaticsintheirquarterlyjournal"Geomatica":Geomaticsisafieldofactivitieswhich,usingasystemicapproach,integratesallthemeansusedtoacquireandmanagespatialdatarequiredaspartofscientific,administrative,legalandtechnicaloperations[业务]involvedintheprocessoftheproductionandmanagementofspatialinformation.〔加拿大测量学会[CanadianInstituteofGeomatics]在他们的季刊"地球空间信息学"中这样定义：测绘学是利用系统的方法,为生产和处理[management]科学的,行政的,法律的[legal]和技术的业务[operations]所需的空间信息,将所有获取和管理空间信息的方法[means]整合在一起的活动领域。[aspartof作为……的一部分,这里不翻译出来]ThedefinitionofGeomaticsisevolving.Aworkingdefinitionmightbe"theart,scienceandtechnologiesrelatedtothemanagementofgeographically-referencedinformation."Geomaticsincludesawiderangeofactivities,fromtheacquisitionandanalysisofsite-specificspatialdatainengineeringanddevelopmentsurveystotheapplicationofGISandremotesensingtechnologiesinenvironmentalmanagement.Itincludescadastralsurveying,hydrographicsurveying,andoceanmapping,anditplaysanimportantroleinlandadministrationandlandusemanagement.〔测绘学定义在发展。现行的一个定义是"涉及工艺、科学和技术的地理信息的处理"。测绘学或地球空间信息学包括一个广泛的生产活动――从工程学和发展了的测量学领域中特殊点的空间数据的获取和分析到GIS和遥感技术在环境管理中的应用。它包括地籍测量、水道测量和海图测量,在土地管理和土地使用中扮演重要的角色。Geomaticsisthemodernscientifictermreferringtotheintegratedapproachofmeasurement,analysis,management,storageanddisplayofthedescriptionsandlocationofEarthbaseddata,oftentermedspatialdata.Thesedatacomefrommanysources,includingearthorbitingsatellites,airandsea-bornesensorsandgroundbasedinstruments.Itisprocessedandmanipulatedwithstate-of-the-artinformationtechnologyusingcomputersoftwareandhardware.Ithasapplicationsinalldisciplineswhichdependonspatialdata,includingenvironmentalstudies,planning,engineering,navigation,geologyandgeophysics,oceanography,landdevelopmentandlandownershipandtourism.Itisthusfundamentaltoallthegeosciencedisciplineswhichusespatiallyrelateddata.〔测绘学是一个现代科学术语,用以表示测量、分析、管理,存储和显示基于地球信息,经常被称为空间数据[oftentermedspatialdata]数据的描述和位置的集成方法。这些数据来自各种数据源,包括地球轨道卫星,空载和舰载传感器及地面仪器。利用计算机软件和硬件,借助现代[state-of-the-art]信息技术。它的应用覆盖所有依赖空间数据的学科,包括环境研究,规划,工程学,导航,地质和地球物理学,海洋学,土地开发,土地经营和旅游学。它因而成为所有使用空间数据地球科学学科的基础。[fromtheSchoolofGeomaticEngineering,Univ.ofNewSouthWales]〔摘自新南威尔士大学测绘[或地球空间信息学]工程学院Geomaticsisconcernedwiththemeasurement,representation,analysis,management,retrievalanddisplayofspatialdataconcerningboththeEarthsphysicalfeaturesandthebuiltenvironment.TheprincipaldisciplinesembracedbyGeomaticsincludethemappingsciences,landmanagement,geographicinformationsystems,environmentalvisualization,geodesy,photogrammetry,remotesensingandsurveying.〔测绘学是测量、表示,分析,处理,重获和显示关于地球物理特征和环境的空间数据的科学。其包括的主要学科有制图学,土地管理,GIS,环境可视化,大地测量学,摄影测量学,遥感和测量学。[fromtheDept.ofGeomaticsatUniv.ofMelbourne]〔摘自墨尔本大学测绘学系[或者地球空间信息学系]Geomaticscomprisesthescience,engineering,andartinvolvedincollectingandmanaginggeographically-referencedinformation.Geographicalinformationplaysanimportantroleinactivitiessuchasenvironmentalmonitoring,managementoflandandmarineresources,andrealestatetransactions.〔测绘学包括自然科学,工程学和工艺或[技术]学；对地理信息的收集与管理。地理信息在环境监测,陆地和海洋资源管理,以及房地产交易[realestate房地产,transaction交易]中扮演重要角色。[fromtheDept.ofGeodesyandGeomaticsEngineeringatUNB]〔摘自加拿大纽布朗斯维克大学测量与大地测量学系ThescienceofGeomaticsisconcernedwiththemeasurement,representation,analysis,management,retrievalanddisplayofspatialinformationdescribingboththeEarth’sphysicalfeaturesandthebuiltenvironment.Geomaticsincludesdisciplinessuchas:Surveying,Geodesy,RemoteSensing&Photogrammetry,Cartography,GeographicInformationSystems,GlobalPositioningSystems.〔测绘学测量,表示,分析,管理,重获和显示空间信息,用来描述地球物理特征和环境。测绘学包括的学科有：测量学,大地测量学,遥感和摄影测量学,制图学,GIS,GPS[fromtheDept.ofSruveyingandSpatialInformationScienceattheUniv.ofTasmania]〔摘自塔斯马尼亚大学,测量与空间信息科学系Unit33DistanceMeasurement〔距离测量Oneofthefundamentalsofsurveyingistheneedtomeasuredistance.〔测量工作的一项基础[fundamental基本原则,同时有基础的意思]是距离测量Distancesarenotnecessarilylinear,especiallyiftheyoccuronthesphericalearth.〔距离不一定指的是直线的,尤其是在地球曲面上的距离InthissubjectwewilldealwithdistancesinEuclideanspace,whichwecanconsiderastraightlinefromonepointorfeaturetoanother.〔这里[Inthissubject翻译成这里],我们所涉及的是欧几里德空间,我们可以认为一条从一点到另一点或一个特征到另一个特征的线是直线。Distancebetweentwopointscanbehorizontal,slope,orvertical.〔两点之间的距离可以是平距、斜距、或者是垂距。Horizontalandslopedistancescanbemeasuredwithlotsoftechniquesofmeasurementdependingonthedesiredqualityoftheresult.〔根据测量结果的精度[quality质量]要求不同,平距或斜距有多种测量方法Ifthepointsareatdifferentelevations,thenthedistanceisthehorizontallengthbetweenplumblinesatthepoints.〔如果这些点在不同高程上,那么平距指的是过点的垂线[plumblines]之间的水平长度。Heregivesabriefsummaryofrelevanttechniquesandtheirrespectiveaccuracies:〔这里给出一个简短的相关[relevant相关的]技术的摘要[summary摘要]和它们各自的[respective各自的]精度PacingandOdometer〔步测和自动计程仪Pacingisaveryusefulformofmeasurementthoughitisnotprecise,especiallywhensurveyorsarelookingforsurveymarksinthefield.〔虽然不精确,但步测是一个非常有用的测量方法[formofmeasurement],尤其是测量者在野外寻找测量标志时。Pacingcanbeperformedatanaccuracylevelof1/100~1/500whenperformedonhorizontalland,whiletheaccuracyofpacingcan’tberelieduponwhenpacingupordownsteephills.〔当在水平场地进行时,步测可以达到1/100到1/500的相对精度,而当地面起伏较大时,这样的精度就不能保证了。Theodometerisasimpledevicethatcanbeattachedtoanyvehicleanddirectlyregistersthenumberofrevolutionsofawheel.〔自动计程仪是一个简单的装置,可以附属于[beattachedto附属于]车辆之上并直接记录[register记录v.]轮子的旋转周数。Withthecircumferenceofthewheelknown,therelationbetweenrevolutionsanddistanceisfixed.〔由于知道了轮子的周长[circumferenceofthewheel轮周],转数[revolution这里有转数的意思]和距离之间的关系就确定下来[fix确定]。OrdinaryTapingandPreciseTaping〔普通尺距测量和精密尺距测量Tapingisaverycommontechniqueformeasuringhorizontaldistancebetweentwopoints.〔尺距测量是测量两点之间平距的非常普遍的方法。Ordinarytapingreferstotheverycommontapesthatwecanbuytheminstores,suchastheplastictapesorpolytapes.〔普通尺距测量使用[refersto引用]的是我们可以在商店里买到的非常普遍的的尺子,例如塑胶尺或涤纶尺。Suchtapeshavelowprecisionindistancemeasurementswithabout1/3000~1/5000.〔这种尺的精度低,测距精度只有1/3000到1/5000Theprecisetapingreferstothesteeltapesandwhicharemuchmoreexpensivethantheplastictapeandhavehigherprecisionof1/10000~1/30000.〔精密尺距测量使用的是比塑胶尺贵的多的钢尺,并具有更高的精度――1/10000到1/30000Invartapesarecomposed35%nickeland65%steel.〔因瓦尺是由35％的镍和65％的钢组成Thisalloyhasaverylowcoefficientofthermalexpansion,makingthetapesusefulinprecisedistancemeasurement.〔这种合金具有非常低的热膨胀[thermalexpansion]系数[coefficient],使得这种尺利于精密距离测量Manytapesarenowgraduatedwithfootunitsononesideandmetricunitsonthereverseside.〔现在许多尺上都在正面标刻[graduate标刻、刻]了英尺计量单位,而在反面标刻了米制计量单位Metricunitsareinmeters,centimeterandminimeterwiththetotallengthof20m,30m,50mand100m.〔米制计量单位是米,厘米和毫米,尺的总长为20m、30m、50m或100mIfwewanttomeasurethehorizontaldistancebetweenthetwopointsAandB,wecandolikethis:〔如果我们想测量A点和B点之间的平距,我们可以这样来做：WithzeroofthetapetothehigherpointBandtapegoingalongthepointA,wecanmeasurethehorizontaldistancebyusingtheplumbbobwithpumplineenteringtothepointA.〔将尺的0刻度对准较高点B点,尺沿向A点,我们可以利用在A点的铅垂[plumbbob]垂线[pumpline应为plumbline垂线]测出平距Tojudgetheexacthorizontalline,weshouldmovethetapeupanddownalongthepumplineandwewillfindthechangesofreadinginthetape.〔为了确定准确的水平线,我们应沿垂线方向上下移动尺子,我们在尺上将得到不同的的读数[changesofreading读数的变化]Theshortestreadingofthetapeisthehorizontaldistance.〔尺子最小的读数就是平距Ifthedistanceislongerthanthelengthoftape,thenwecandividethelongdistanceintoseveralsegmentsandgetthetotaldistancebypluseachsegmenttogether.〔如果距离比尺长要长,那么[then]我们可以将其分成几段[segment],把每段长加起来获得总长。Sincedifferenttapeshavedifferentstartsofzeroofthetapes,itisveryimportanttojudgewherethezeroofthetapebegins.〔由于不同的尺有不同的0刻度,判断尺的0刻度在哪儿十分重要。TacheometryandStadia〔视距测量和视距仪Tacheometryisanopticalsolutiontothemeasurementofdistance.〔视距测量是一个光学[optical]测距方法ThewordisderivedfromtheGreekTacns,meaning"swift",andmetrot,meaning"ameasure".〔这个词源自于[isderivedfrom源自于]希腊语的Tacns,意思是"迅速的",和metrot[同样是希腊语],意思是"方法"。Tacheometryinvolvesthemeasurementofarelateddistanceparameter[参数]eitherbymeansofafixed-angleintercept.〔视距测量包括一个相关距离参数的测量和依靠定角截距的测量[bymeansof依靠][either表示并列]Theodolitetacheometryisanexampleofstadiasystem.〔经纬仪视距测量就是视距仪器的一个例子Thetheodoliteisdirectedatthelevelstaffwherethestaffisheldverticallyandthelineofsightofthetelescopeishorizontal.〔将经纬仪[isdirectedat被动语态,翻译为将；directat对准……]对准水准尺[levelstaff],水准尺竖直,望远镜的视线[可以翻译为视准轴]水平。ByreadingthetopandbottomstadiahairsonthetelescopeviewandthenthehorizontaldistancefromcenterofinstrumenttorodcanbeobtainedbymultiplyingthestadiaintervalfactorKbythestadiaintervalandplusthedistanceCwhichisfromthecenterofinstrumenttoprincipalfocus,i.e.D=Ks+C.〔通过望远镜视野[view]里的上下视距丝读数,从仪器到尺的平距可以用视距常数[stadiaintervalfactor]K乘视距间隔[stadiainterval]加上从仪器中心到主焦点[principalfocus]的距离C得到。也就是[i.e.拉丁文？],D=Ks+CUsuallythenominalstadiaintervalfactorKequals100whichisaconstantforaparticularinstrumentaslongasconditionsremainunchanged,butitmaybedeterminedbyobservationinpractice.〔通常,名义上的视距常数K等于100,只要[aslongas]条件保持不变,它就是个特别装置的[particularinstrument指代视距装置]常数[constant常数]但在实践中可以通过观测确定ThevalueofCisdeterminedbythemanufacturerandstatedontheinsideoftheinstrumentbox.〔C值由厂商决定并固定在仪器之内Forexternal-focusingtelescopes,underordinarycondition,Cmaybeconsideredas1ftwithouterrorofconsequence.〔对于外调焦望远镜,通常情况下,C被认为是1英尺而不会给结果带来错误。Internal-focusingtelescopesaresoconstructedthatCis0ornearlyso;thisisanadvantageofinternal-focustelescopesforstadiawork.〔内调焦望远镜因此被发明[construct建立、创立],C为或近似为0；这是内调焦望远镜在视距测量中的一个优点。Mostinstrumentsnowusedforstadiaareequippedwithinternal-focusingtelescopes.〔现在大多数视距仪器都使用内调焦望远镜Applicationsoftacheometryincludetraversingandlevelingforthetopographicsurveys,locationofdetailsurveys,levelingandfieldcompletionsurveysforthetopographicmapping,andhydrographicmapping.〔视距测量的应用包括地形测量[topographicsurvey]中的导线测量[traversing]和水准测量[leveling]工作,细部测量[detailsurvey]中的定位,绘制地形图工作中的水准测量和野外完全化测量,以及水道测图Therelativeprecisionis1:1000to1:5000.〔其相对精度为1:1000到1:5000Stadiaisaformoftacheometrythatusesatelescopiccross-hairconfigurationtoassistindeterminingdistances.〔视距仪是视距测量的一种形式,利用望远镜的十字丝结构帮助测距Aseriesofrodreadingsistakenwithatheodoliteandtheresultantintervalsareusedtodeterminedistances.〔一系列的标尺读数由经纬仪测出,并且籍此而得到视距间隔,用来确定距离[resultant由此产生的]ElectronicDistanceMeasurement<EDM>〔电子测距仪TheElectronicDistanceMeasurement<EDM>wasfirstintroducedin1950sbythefoundersofGeodimeterInc.〔电子测距仪的概念是由Geodimeter["光电测距仪"――商标名]公司的创始人在20世纪50年代引入的。TheadventofEDMinstrumenthascompletelyrevolutionizedallsurveyingprocedures,resultinginachangeofemphasisandtechniques.〔EDM测量手段的出现[advent]是对所有测量手段的完全的革命[revolutionized革命化的],导致[resultin]了一场技术革命[change]和侧重点的改变。[emphasis侧重点]Distancecannowbemeasuredeasily,quicklyandwithgreataccuracy,regardlessofterrainconditions.〔现在距离可以被很容易、快速和精确的测量,而又不受地形[terrain]影响。EDMinstrumentsrefertothedistancemeasurementequipmentsusinglightandradiowaves.〔EDM是利用光波和无线电波测距的设备[referto译为"是"]Bothlightwavesandradiowavesareelectromagnetic.〔光波和无线电波都是电磁波[electromagnetic电磁的]Theyhaveidenticalvelocitiesinavacuum<orspace>to299,792.458±0.001km/sec.〔它们在真空中都有一样的速度299,792.458±0.001km/secThesevelocities,whichareaffectedbytheair’sdensity,arereducedandneedtoberecalculatedintheatmosphere.〔它们的速度,由于会收到空气密度的影响而降低,在大气中需要重新计算[recalculate]ThebasicprincipleofEDMinstrumentsisthatdistanceequalstimemultipliedbyvelocity.〔EDM的基本原理是距离等于时间乘速度Thusifthevelocityofaradioorlightwaveandtimerequiredforittogofromonepointtoanotherareknown,thedistancebetweenthetwopointscanbecalculated.〔这样,如果无线电波或光波的速度和其从一点到另一点所需的时间已知了,两点之间的距离就可以计算出来TheEDMinstrumentsmaybeclassifiedaccordingtothetypeandwavelengthoftheelectromagneticenergygeneratedoraccordingtotheiroperationalrange.〔可以依照产生[generate]的电磁能量[电磁波]的类型和波长或根据它们的运作范围[工作范围]给EDM分类。EDMinstrumentsusethreedifferentwavelengthbands:<1>Microwavesystemswithrangeupto150km,wavelength3cm,notlimitedtolineofsightandunaffectedbyvisibility;<2>Lightwavesystemswithrangeupto5km<forsmallmachines>,visiblelight,lasersanddistancereducedbyvisibility;<3>Infraredsystemswithrangeupto3km,limitedtolineofsightandlimitedbyrain,fog,otherairborneparticles.〔EDM使用三种不同波长的波段：<1>微波系统[波段],其测距范围达150km,波长3cm,不受限于视线范围,也不受可见度的影响；<2>可见光波段,有效范围5km〔小型仪器,可见光、激光,其距离受可见度的影响会降低；<3>红外线[Infrared]波段,测程3km,受限于视线范围,并且受限于空气中的微粒影响AlthoughthereisawidevarietyofEDMinstrumentsavailablewithdifferentwavelengths,therearebasicallyonlytwomethodsofmeasurementemployedwhichmaydividetheinstrumentsintotwoclassificationaselectro-optical<lightwaves>andmicrowaves<radiowaves>instruments.〔尽管不同的EDM用到不同的波长,基本上只有两种测量方法在使用,可以将其[即EDM]分为光电测距仪和微波测距仪Thesetwobasicmethodsarenamelythepulsemethodandmorepopularphasedifferentmethod.〔这两种基本方法即[namely即]脉冲[pulse]法和更流行的相位[phasedifferent相位的不同]法Theyfunctionbysendinglightwavesormicrowavesalongthepathtobemeasuredandmeasuringthetimedifferencesbetweentransmittedandreceivedsignals,orinmeasuringthephasedifferencesbetweentransmittedandreceivedsignalsinreturningthereflectinglightwavetosource.〔沿着要测的路径发射光波或微波,并测出发射和收到反射信号之间的时间间隔,或者是测出发射和接受反射信号之间的相差[phasedifferences],它们通过这种方法来运行[functionv.]ModernEDMinstrumentsarefullyautomatictosuchanextentthat,aftertheinstruments,setupononestation,emitsamodulatedlightbeamtoapassivereflectorsetupontheotherendofthelinetobemeasured.〔现代的EDM全自动化到这样的程度[tosuchanextentthat到这样的程度],在一个站点安置,需测距离线的另一处安置有反射棱镜,发射一束已调制[modulated已调制的]的光束到棱镜上Theoperatorneedonlydepressabutton,andtheslopedistanceisautomaticallydisplayed.〔操作者仅仅需要按一个键,斜距就自动显示出来。MorecompleteEDMinstrumentsalsohavethecapabilityofmeasuringhorizontalandverticalorzenithanglesaswellastheslopedistance.〔更完全的[功能更完备的]EDM还具有测水平角、竖直角和天顶角的功能Theseinstrumentsreferredtoastotalstationinstruments.〔这种仪器被称为全站仪Unit4AngleandDirectionMeasurement〔角度和方向测量Horizontalandverticalanglesarefundamentalmeasurementsinsurveying.〔水平角和竖直角是测量的基本测量工作Itisnecessarytobefamiliarwiththemeaningsofcertainbasictermsbeforedescribingangleanddirectionmeasurement.〔在描述角度和方向测量之前,有必要熟悉[befamiliarwith熟悉]几个[certain某些]基本术语的含义[meaning]Thetermsdiscussedherehavereferencetotheactualfigureoftheearth.〔这里讨论的这些术语与地球的真实形状有关[havereferenceto与……有关]BasicTerms〔基本术语Averticallineatanypointontheearth’ssurfaceisthelinethatfollowsthedirectionofgravityatthatpoint.〔地球表面任一点的垂线是指这点上沿着重力的方向的线[可译为：地球表面任一点的垂线方向是过该点的重力方向]Itisthedirectionthatastringwillassumeifaweightisattachedatthatpointandthestringissuspendedfreelyatthepoint.〔如果在这点上用线悬挂一个重物,当线自由[即无干扰]静止[suspended暂停的、悬浮的]时,这条线所呈现[assume呈现]的方向即重力方向。Atagivenpointthereisonlyoneverticalline.〔在给定的一个点上只有一条垂线。Ahorizontallineatapointisanylinethatisperpendiculartotheverticallineatthepoint.〔一点上的水平线是垂直[perpendicular垂直的]于过该点的垂线的直线。Atanypointthereareanunlimitednumberofhorizontallines.〔过任一点的水平线有无数[unlimited]条。Ahorizontalplaneatapointistheplanethatisperpendiculartotheverticallineatthepoint.〔过一点的水平面是垂直于过该点的垂线的平面Thereisonlyonehorizontalplanethroughagivenpoint.〔过给定的一个点只有一个水平面Averticalplaneatapointisanyplanethatcontainstheverticallineatthepoint.〔过一点的竖直面是包含[contain]过该点的垂线的任一平面Thereareanunlimitednumberofverticalplanesatagivenpoint.〔过给定的一点有无数个竖直面HorizontalAngleandVerticalAngle〔水平角和竖直角Ahorizontalangleistheangleformedinahorizontalplanebytwointersectingverticalplanes,orahorizontalanglebetweentwolinesistheanglebetweentheprojectionsofthelinesontoahorizontalplane.〔水平角是指在一个水平面内由两相交[intersect相交v.]的竖直面形成的角,或者说,两条线之间的水平角是这两条线在水平面上的投影线的夹角Forexample,observationstodifferentelevationpointsBandCfromAwillgivethehorizontalangle∠bacwhichistheanglebetweentheprojectionsoftwolines<ABandAC>ontothehorizontalplane.〔例如,在A点观测不同高度的B和C点,其水平角∠bac是由AB和AC两条线在水平面上的投影构成的Itfollowsthat,althoughthepointsobservedareatdifferentelevations,itisalwaysthehorizontalangleandnotthespaceanglethatismeasured<Figure1>.〔由此得出结论[Itfollowsthat由此得出结论],虽然被观测的点在不同的高度上,测出的总是水平角而不是空间角。Thehorizontalangleisusedprimarilytoobtainrelativedirectiontoasurveycontrolpoint,ortopographicdetailpoints,ortopointstobesetout.〔水平角主要[primarily]用来由联测控制点获得相对方向,或者地形测量碎部点、或者放样点[ortopointstobesetout应该是orpointstobesetout才对吧？？？directiontoasurveycontrolpoint、topographicdetailpoints、pointstobesetout并列都是obtain的宾语。]Averticalangleisananglemeasuredinaverticalplanewhichisreferencedtoahorizontallinebyplus<up>orminus<down>angles,ortoaverticallinefromthezenithdirection.〔竖直角是在一个竖直面内参考于[reference参考]水平线的正〔仰角或负〔俯角,或者相对于一个天顶方向的垂线的角Plusandminusverticalanglesaresometimesreferredtoaselevationordepressionangles,respectively.〔正负竖直角有时分别[respectively分别地]被称为仰角[elevationangle]或俯角[depressionangle]Averticalanglethusliesbetween0°and±90°.〔竖直角位于[lie位于]0～90度之间Zenithisthetermdescribingpointsonacelestialspherethatisasphereofinfinitelylargeradiuswithitscenteratthecenteroftheearth.〔天顶方向是一个术语,用来描述在天球[celestialsphere天球]上的点,天球是一个半径无限[infinitely无限地]大的球,其中心在地球中心。Thezenithisananglemeasuredinaverticalplanedownwardfromanupwarddirectedverticallinethroughtheinstrument.〔天顶距是一个在竖直面内从一个过仪器的被定向为向上的竖直方向线向下测量的角。Itisthusbetween0°and180°.〔它的范围是从0到180度Obviouslythezenithangleisequalto90°minustheverticalangles.〔显然,天顶距等于90度减去竖直角Verticalanglesorzenithsareusedinthecorrectionofslopedistancetothehorizontalorinheightdetermined.〔竖直角或天顶距用于斜距化平距的改正或者高程的测量Forthemostpart,theinstrumentusedinthemeasurementofanglesiscalled