Unit4AngleMeasurement（2）HeNanGeologyMinaralCollegeYangLikun01AngleMeasurementCONTENTS目錄02OtherhorizontalanglesPARTONEAngleMeasurement01AngleMeasurementAhorizontalangleinsurveyinghasadirection;thatis,itismeasuredordesignedtotherightortotheleft,oritisconsideredclockwiseorcounterclockwise.在測(cè)的水平角有方向，就是說(shuō)它是向左測(cè)還是向右測(cè)，或者是說(shuō)，順時(shí)針測(cè)還是逆時(shí)針測(cè)。AngleMeasurementPABabpbhorizontalplaneIntheabovefigure,theangleatAfromBtoCisclockwiseandtheanglefromCtoBiscounterclockwise.如上圖所示，在A點(diǎn)由B到C就是順時(shí)針角，而從C到B就是逆時(shí)針角。

AngleMeasurementWiththetheodolitesetup,centered,andleveledoveratstationA,thenasimplehorizontalanglemeasurementbetweensurveyingpointB,AandCwouldbetakenasfollows:經(jīng)緯儀在A點(diǎn)安置、對(duì)中、整平后，在B、A和C測(cè)量點(diǎn)間的簡(jiǎn)單的水平角測(cè)量可以按下列步驟進(jìn)行：AngleMeasurement⑴Faceleft,thetargetsetatsurveypointBiscarefullybisectedandthereadingonhorizontalscaleis25°.“盤左”，用豎絲將B點(diǎn)的目標(biāo)仔細(xì)平分，水平度盤讀數(shù)為25度。AngleMeasurement⑵TheupperplateclampisreleasedandtelescopeisturnedclockwisetosurveypointC.Thereadingonhorizontalcircleis75°。水平度盤制動(dòng)螺旋松開，順時(shí)針轉(zhuǎn)動(dòng)望遠(yuǎn)鏡至C點(diǎn)，水平度盤讀數(shù)75度。clamp

夾具，夾鉗；車輪固定夾；AngleMeasurement⑶Thehorizontalangleisthenthedifferenceofthetwodirections,thatis,(75°-25°)=50°水平角就是兩個(gè)方向值的差值，即，(75°-25°)=50°AngleMeasurement⑷ChangefaceandobservepointCon“faceright”,andnotethereading=255°換度盤方向至盤右并照準(zhǔn)C點(diǎn)，記下讀數(shù)為255度。AngleMeasurement⑸ReleaseupperplateandswingcounterclockwisetopointBandnotethereading=205°松開水平度盤，逆時(shí)針旋轉(zhuǎn)至B點(diǎn)并記下讀數(shù)為205度。AngleMeasurement⑹Thereadingorthedirectionmustbesubtractedinthesameorderas255°-205°=50°讀數(shù)或者說(shuō)是方向值按同樣的法則相減，255°-205°=50°AngleMeasurement⑺Themeanoftwovalueswouldbeacceptediftheyareinacceptableagreement.如果兩個(gè)減出來(lái)的值的一致性在誤差范圍之內(nèi)的是可接受的，取兩個(gè)值的平均值。AngleMeasurementModernelectronicdigitaltheodolitescontaincircularencodersthatsensetherotationsofthespindlesandthetelescope,converttheserotationsintohorizontalandvertical(orzenith)angleselectronically,anddisplaythevalueoftheanglesonliquidcrystaldisplays(LCDs)orlight-emittingdiodedisplays(LEDs).現(xiàn)代的電子數(shù)字經(jīng)緯儀包含編碼度盤，能夠感知軸和望遠(yuǎn)鏡的旋轉(zhuǎn)，并使之電子地轉(zhuǎn)換為水平角度和豎直角度，并在液晶顯示器或發(fā)光二極管顯示器上顯示出來(lái)。AngleMeasurementThesereadoutscanberecordedinaconventionalfieldbookorcanbestoredinadatacollectorforfutureprintoutorcomputation.這些顯示可以被一個(gè)傳統(tǒng)的野外電子手簿或數(shù)據(jù)存儲(chǔ)卡記錄，以便日后打印或計(jì)算。AngleMeasurementTheinstrumentcontainsapendulumcompensatororsomeotherprovisionforindexingtheverticalcirclereadingstoanabsoluteverticaldirection.這種儀器具有一個(gè)懸掛補(bǔ)償器或其它裝置，使豎盤指標(biāo)讀數(shù)指向一個(gè)絕對(duì)豎直方向。AngleMeasurementThecirclecanbesettozeroreadingsbyasimplepressofabuttonorinitializedtoanyvalueontheinstrument.這個(gè)度盤可以通過(guò)簡(jiǎn)單的按一個(gè)鍵就將其置零，或初始化成任一值。PARTTWOOtherhorizontalangles02Otherhorizontalangles1.Azimuth:Azimuthisthehorizontalanglemeasuredinaclockwisedirectionfromtheplaneofthemeridian,whichisalineonthemeansurfaceoftheearthjoiningthenorthandsouthpoles.方位角是從子午面起算按順時(shí)針旋轉(zhuǎn)的角，子午線是在地球平均表面連接北極與南極的線。OtherhorizontalanglesAzimuthrangesinmagnitudefrom0°to360°,valuesinexcessof360°,whicharesometimesencounteredincomputations,aresimplyreducedby360°beforefinallisting.方位角的取值范圍從0度到360度，超過(guò)360的值――有時(shí)會(huì)在計(jì)算時(shí)遇到，只需減去360度即可。Otherhorizontalangles2.Bearing:Bearingisthetraditionalwayofstatingtheorientationoftheline.Itisactuallytheanglemeasuredfromthenorthorsouth.象限角是一種傳統(tǒng)的描述直線方向的方法。實(shí)際上，它是從南或北方向開始量測(cè)的角。OtherhorizontalanglesThebearing,whichcanbemeasuredclockwiseorcounterclockwisefromthenorthorsouthendofthemeridian,isalwaysaccompaniedbylettersthatlocatethequadrantinwhichthelinefalls.象限角可以從子午線北端或南端以順時(shí)針或逆時(shí)針量測(cè)，總是伴以字母，用來(lái)定位直線所落在的象限。OtherhorizontalanglesForexample,bearingN32Windicatesalinetrending32°westofthenorth.例如：象限角N32W代表一條直線從北方向轉(zhuǎn)向西方向32度。OtherhorizontalanglesItisequaltoanazimuthof328°.BearingS12Windicatesalinetrending12°westofthesouth.Itisequalto