《测绘专业英语》课件-3-Angle Measurement

Unit3AngleMeasurement（1）HeNanGeologyMinaralCollegeYangLikun01BasicTermsCONTENTS目录03VerticalAngle02HorizontalAngle04InstrumentforanglesmeasurementPARTONEBasicTerms01BasicTerms1.verticalline

：Averticallineatanypointontheearth’ssurfaceisthelinethatfollowsthedirectionofgravityatthatpoint.Itisthedirectionthatastringwillassumeifaweightisattachedatthatpointandthestringissuspendedfreelyatthepoint.Atagivenpointthereisonlyoneverticalline.地球表面任一点的垂线是指这点上沿着重力的方向的线。如果在这点上用线悬挂一个重物，当线自由静止时，这条线所呈现的方向即重力方向。在给定的一个点上只有一条垂线。suspendedadj.暂停的、悬浮的assumev.呈现2.horizontalline：Ahorizontallineatapointisanylinethatisperpendiculartotheverticallineatthepoint.Atanypointthereareanunlimitednumberofhorizontallines.一点上的水平线是垂直于过该点的垂线的直线。过任一点的水平线有无数条。beperpendicularto垂直于……BasicTerms3.horizontalplane：Ahorizontalplaneistheplanethatisperpendiculartotheverticallineatthepoint.Thereisonlyonehorizontalplanethroughagivenpoint.过一点的水平面是垂直于过该点的垂线的平面。过给定的一个点只有一个水平面。BasicTerms4.verticalplane:Averticalplaneatapointisanyplanethatcontainstheverticallineatthepoint.Thereareanunlimitednumberofverticalplanesatagivenpoint.过一点的竖直面是包含过该点的垂线的任一平面。过给定的一点有无数个竖直面。BasicTermsPARTTWOHorizontalAngle02HorizontalAngleAhorizontalangleistheangleformedinahorizontalplanebytwointersectingverticalplanes,orahorizontalanglebetweentwolinesistheanglebetweentheprojectionsofthelinesontoahorizontalplane.水平角是指在一个水平面内由两相交的竖直面形成的角，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。intersectv.相交，交叉PABabpbhorizontalplaneFigure1Forexample,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。HorizontalAngleItfollowsthat,althoughthepointsobservedareatdifferentelevations,itisalwaysthehorizontalangleandnotthespaceanglethatismeasured(Figure1).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。HorizontalAngleThehorizontalangleisusedprimarilytoobtainrelativedirectiontoasurveycontrolpoint,ortopographicdetailpoints,ortopointstobe

setout.水平角主要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。HorizontalAnglePARTTHREEVerticalAngle03Averticalangleisananglemeasuredinaverticalplanewhichisreferencedtoahorizontallinebyplus(up)orminus(down)angles,ortoaverticallinefromthezenithdirection.竖直角是在一个竖直面内参考于水平线的正（仰）角或负（俯）角，或者相对于一个天顶方向的垂线的角。VerticalAnglePlusandminusverticalanglesaresometimesreferredtoaselevationordepressionangles,respectively.正负竖直角有时分别被称为仰角或俯角。VerticalAngleAverticalanglethusliesbetween0°and±90°.竖直角位于0～90度之间。liev.位于VerticalAngleZenithisthetermdescribingpointsonacelestialspherethatisasphereofinfinitelylargeradiuswithitscenteratthecenteroftheearth.天顶方向是一个术语，用来描述在天球上的点，天球是一个半径无限大的球，其中心在地球中心。celestialsphere/səˈlestiəl//səˈlestʃ(ə)l/adj.天空的，天上的天球infinitely无限地VerticalAngleThezenithisananglemeasuredinaverticalplanedownwardfromanupwarddirectedverticallinethroughtheinstrument.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。VerticalAngleItisthusbetween0°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。VerticalAngleVerticalanglesorzenithsareusedinthecorrectionofslopedistancetothehorizontalorinheightdetermined.竖直角或天顶距用于斜距化平距的改正或者高程的测量。

VerticalAnglePARTFOURInstrumentusedanglesmeasurement04InstrumentusedanglesmeasurementForthemostpart,theinstrumentusedinthemeasurementofanglesiscalledatransitortheodolite,althoughanglescanbemeasuredwithclinometers,sextants,orcompasses.在极大程度上，用来测角的工具被称为经纬仪，虽然角度可以用倾斜仪、六分仪、或罗盘仪来测.Thetheodolitecontainsahorizontalandverticalcirclesofeitherglassorsilver.经纬仪有一个玻璃的或镀银的水平度盘和竖直度盘。InstrumentusedanglesmeasurementThehorizontalandverticalcirclesoftheodolitecanbelinkedtocircularprotractors

graduatedfrom0°to360°inaclockwisemannersetinhorizontalandverticalplane.经纬仪的水平度盘和竖直度盘与顺时针刻了0到360度刻划的圆量角器相连。InstrumentusedanglesmeasurementInstrumentusedanglesmeasurementThehorizontalcircleisusedwhenmeasuringorlayingoffhorizontalanglesandtheverticalcircleisusedtomeasureorlayoffverticalanglesorzenithangles.测或放样水平角时用水平度盘，测或放样竖直角或天顶距时用竖直度盘。layoff拨、放样Instrumentus