《测绘专业英语》课件-4-Angle Measurement

Unit4AngleMeasurement（2）HeNanGeologyMinaralCollegeYangLikun01AngleMeasurementCONTENTS目录02OtherhorizontalanglesPARTONEAngleMeasurement01AngleMeasurementAhorizontalangleinsurveyinghasadirection;thatis,itismeasuredordesignedtotherightortotheleft,oritisconsideredclockwiseorcounterclockwise.在测的水平角有方向，就是说它是向左测还是向右测，或者是说，顺时针测还是逆时针测。AngleMeasurementPABabpbhorizontalplaneIntheabovefigure,theangleatAfromBtoCisclockwiseandtheanglefromCtoBiscounterclockwise.如上图所示，在A点由B到C就是顺时针角，而从C到B就是逆时针角。

AngleMeasurementWiththetheodolitesetup,centered,andleveledoveratstationA,thenasimplehorizontalanglemeasurementbetweensurveyingpointB,AandCwouldbetakenasfollows:经纬仪在A点安置、对中、整平后，在B、A和C测量点间的简单的水平角测量可以按下列步骤进行：AngleMeasurement⑴Faceleft,thetargetsetatsurveypointBiscarefullybisectedandthereadingonhorizontalscaleis25°.“盘左”，用竖丝将B点的目标仔细平分，水平度盘读数为25度。AngleMeasurement⑵TheupperplateclampisreleasedandtelescopeisturnedclockwisetosurveypointC.Thereadingonhorizontalcircleis75°。水平度盘制动螺旋松开，顺时针转动望远镜至C点，水平度盘读数75度。clamp

夹具，夹钳；车轮固定夹；AngleMeasurement⑶Thehorizontalangleisthenthedifferenceofthetwodirections,thatis,(75°-25°)=50°水平角就是两个方向值的差值，即，(75°-25°)=50°AngleMeasurement⑷ChangefaceandobservepointCon“faceright”,andnotethereading=255°换度盘方向至盘右并照准C点，记下读数为255度。AngleMeasurement⑸ReleaseupperplateandswingcounterclockwisetopointBandnotethereading=205°松开水平度盘，逆时针旋转至B点并记下读数为205度。AngleMeasurement⑹Thereadingorthedirectionmustbesubtractedinthesameorderas255°-205°=50°读数或者说是方向值按同样的法则相减，255°-205°=50°AngleMeasurement⑺Themeanoftwovalueswouldbeacceptediftheyareinacceptableagreement.如果两个减出来的值的一致性在误差范围之内的是可接受的，取两个值的平均值。AngleMeasurementModernelectronicdigitaltheodolitescontaincircularencodersthatsensetherotationsofthespindlesandthetelescope,converttheserotationsintohorizontalandvertical(orzenith)angleselectronically,anddisplaythevalueoftheanglesonliquidcrystaldisplays(LCDs)orlight-emittingdiodedisplays(LEDs).现代的电子数字经纬仪包含编码度盘，能够感知轴和望远镜的旋转，并使之电子地转换为水平角度和竖直角度，并在液晶显示器或发光二极管显示器上显示出来。AngleMeasurementThesereadoutscanberecordedinaconventionalfieldbookorcanbestoredinadatacollectorforfutureprintoutorcomputation.这些显示可以被一个传统的野外电子手簿或数据存储卡记录，以便日后打印或计算。AngleMeasurementTheinstrumentcontainsapendulumcompensatororsomeotherprovisionforindexingtheverticalcirclereadingstoanabsoluteverticaldirection.这种仪器具有一个悬挂补偿器或其它装置，使竖盘指标读数指向一个绝对竖直方向。AngleMeasurementThecirclecanbesettozeroreadingsbyasimplepressofabuttonorinitializedtoanyvalueontheinstrument.这个度盘可以通过简单的按一个键就将其置零，或初始化成任一值。PARTTWOOtherhorizontalangles02Otherhorizontalangles1.Azimuth:Azimuthisthehorizontalanglemeasuredinaclockwisedirectionfromtheplaneofthemeridian,whichisalineonthemeansurfaceoftheearthjoiningthenorthandsouthpoles.方位角是从子午面起算按顺时针旋转的角，子午线是在地球平均表面连接北极与南极的线。OtherhorizontalanglesAzimuthrangesinmagnitudefrom0°to360°,valuesinexcessof360°,whicharesometimesencounteredincomputations,aresimplyreducedby360°beforefinallisting.方位角的取值范围从0度到360度，超过360的值――有时会在计算时遇到，只需减去360度即可。Otherhorizontalangles2.Bearing:Bearingisthetraditionalwayofstatingtheorientationoftheline.Itisactuallytheanglemeasuredfromthenorthorsouth.象限角是一种传统的描述直线方向的方法。实际上，它是从南或北方向开始量测的角。OtherhorizontalanglesThebearing,whichcanbemeasuredclockwiseorcounterclockwisefromthenorthorsouthendofthemeridian,isalwaysaccompaniedbylettersthatlocatethequadrantinwhichthelinefalls.象限角可以从子午线北端或南端以顺时针或逆时针量测，总是伴以字母，用来定位直线所落在的象限。OtherhorizontalanglesForexample,bearingN32Windicatesalinetrending32°westofthenorth.例如：象限角N32W代表一条直线从北方向转向西方向32度。OtherhorizontalanglesItisequaltoanazimuthof328°.BearingS12Windicatesalinetrending12°westofthesouth.Itisequalto