测绘工程专业英语复习资料Word文档下载推荐.docx
- 文档编号:20489358
- 上传时间:2023-01-23
- 格式:DOCX
- 页数:9
- 大小:25.16KB
测绘工程专业英语复习资料Word文档下载推荐.docx
《测绘工程专业英语复习资料Word文档下载推荐.docx》由会员分享,可在线阅读,更多相关《测绘工程专业英语复习资料Word文档下载推荐.docx(9页珍藏版)》请在冰豆网上搜索。
surveyor:
Theterm“surveyor”istraditionallyusedtocollectivelydescribethoseengagedintheaboveactivities.
Unit2GeodeticSurveyingandPlaneSurveying
GeodeticSurveying:
Thetypeofsurveyingthattakesintoaccountthetrueshapeoftheearthiscalledgeodeticsurveying.Thistypeofsurveyissuitedforlargeareasandlonglinesandisusedtofindthepreciselocationofbasicpointsneededforestablishingcontrolforothersurveys.
Ingeodeticsurveys,thestationsarenormallylongdistancesapart,andmorepreciseinstrumentsandsurveyingmethodsarerequiredforthistypeofsurveyingthanforplanesurveying.
Geodeticcontrolsurveypoints:
Widelyspaced,permanentmonumentsserveasthebasisforcomputinglengthsanddistancesbetweenrelativepositions.Thesebasicpointswithpermanentmonumentsarecalledgeodeticcontrolsurveypoints,whichsupporttheproductionofconsistentandcompatibledataforsurveyingandmappingprojects.
PlaneSurveying:
Thetypeofsurveyinginwhichthemeansurfaceoftheearthisconsideredaplane,orinwhichthecurvatureoftheearthcanbedisregardedwithoutsignificanterror,generallyiscalledplanesurveying.
Thetermisusedtodesignatesurveyworkinwhichthedistances
orareasinvolvedareoflimitedextent.
thecurvatureoftheearthmustbetakenintoconsiderationonlyinprecise
surveysoflargeareas.
Surveysforthelocationandconstructionofhighways,railroads,canals,andingeneral,thesurveysnecessaryfortheworksofhumanbeingsareplanesurveys,asarethesurveysmadetoestablishboundaries,exceptstateandnational.
Thereisclosecooperationbetweengeodeticsurveyingandplanesurveying.Thegeodeticsurveyadoptstheparametersdeterminedbymeasurementsoftheearth,anditsownresultsareavailabletothosewhomeasuretheearth.Theplanesurveys,inturn,aregenerallytiedtothecontrolpointsofthegeodeticsurveysandserveparticularlyinthedevelopmentofnationalmapseriesandintheformationofrealestatecadastres.
Unit3DistanceMeasurement
ElectronicDistanceMeasurement(EDM):
EDMinstrumentsrefertothedistancemeasurementequipmentsusinglightandradiowaves.Bothlightwavesandradiowavesareelectromagnetic.TheadventofEDMinstrumenthascompletelyrevolutionizedallsurveyingprocedures,resultinginachangeofemphasisandtechniques.
优点:
Distancecannowbemeasuredeasily,quicklyandwithgreataccuracy,regardlessofterrainconditions.
分类:
TheEDMinstrumentsmaybeclassifiedaccordingtothetypeandwavelengthoftheelectromagneticenergygeneratedoraccordingtotheiroperationalrange.EDMinstrumentsusethreedifferentwavelengthbands:
(1)Microwavesystemswithrangeupto150km,wavelength3cm,notlimitedtolineofsightandunaffectedbyvisibility;
(2)Lightwavesystemswithrangeupto5km(forsmallmachines),visiblelight,lasersanddistancereducedbyvisibility;
(3)Infraredsystemswithrangeupto3km,limitedtolineofsightandlimitedbyrain,fog,otherairborneparticles.
两种方法:
Therearebasicallytwomethodsofmeasurementemployedwhichmaydividetheinstrumentsintotwoclassificationaselectro-optical(lightwaves)andmicrowaves(radiowaves)instruments.Thesetwobasicmethodsarenamelythepulsemethodandmorepopularphasedifferentmethod.Theyfunctionbysendinglightwavesormicrowavesalongthepathtobemeasuredandmeasuringthetimedifferencesbetweentransmittedandreceivedsignals,orinmeasuringthephasedifferencesbetweentransmittedandreceivedsignalsinreturningthereflectinglightwavetosource.
Unit4AngleandDirectionMeasurement
Averticalline:
Averticallineatanypointontheearth’ssurfaceisthelinethatfollowsthedirectionofgravityatthatpoint.Itisthedirectionthatastringwillassumeifaweightisattachedatthatpointandthestringissuspendedfreelyatthepoint.Atagivenpointthereisonlyoneverticalline.
Ahorizontalline:
Ahorizontallineatapointisanylinethatisperpendiculartotheverticallineatthepoint.Atanypointthereareanunlimitednumberofhorizontallines.
Ahorizontalplane:
Ahorizontalplaneatapointistheplanethatisperpendiculartotheverticallineatthepoint.Thereisonlyonehorizontalplanethroughagivenpoint.
Averticalplane:
Averticalplaneatapointisanyplanethatcontainstheverticallineatthepoint.Thereareanunlimitednumberofverticalplanesatagivenpoint.
Ahorizontalangle:
Ahorizontalangleistheangleformedinahorizontalplanebytwointersectingverticalplanes,orahorizontalanglebetweentwolinesistheanglebetweentheprojectionsofthelinesontoahorizontalplane.
Averticalangle:
Averticalangleisananglemeasuredinaverticalplanewhichisreferencedtoahorizontallinebyplus(up)orminus(down)angles,ortoaverticallinefromthezenithdirection.
Zenith:
Zenithisthetermdescribingpointsonacelestialspherethatisasphereofinfinitelylargeradiuswithitscenteratthecenteroftheearth.
Azimuth:
Azimuthisthehorizontalanglemeasuredinaclockwisedirectionfromtheplaneofthemeridian,whichisalineonthemeansurfaceoftheearthjoiningthenorthandsouthpoles.
Bearing:
Bearingisthetraditionalwayofstatingtheorientationoftheline.Itisactuallytheanglemeasuredfromthenorthorsouth.
Unit5Traversing
Traversing:
Asurveytraverseisasequenceoflengthsanddirectionsoflinesbetweenpointsontheearth,obtainedbyorfromfieldangleanddistancemeasurementsandusedindeterminingpositionsofthepoints.Ingeneral,atraverseisalwaysclassifiedaseitheranopentraverseoraclosedtraverse.
Anopentraverse:
Anopentraverseoriginateseitheratapointofknownhorizontalpositionwithrespecttoahorizontaldatumoratanassumedhorizontalposition,andterminatesatastationwhoserelativepositionisnotpreviouslyknown.
Aclosedtraverse:
Aclosedtraversecanbedescribedinanyoneofthefollowingtwoways:
(1)Aclosedlooptraverse,asthenameimplies,formsacontinuousloop,enclosinganarea.Thistypeofclosedtraversestartsatassumedhorizontalpositionorataknownhorizontalpositionwithrespecttoahorizontaldatumandendsatthesamepoint.
比较:
Theopentraverseprovidesnocheckagainstmistakesandlargeerrorsforitsterminationatanunknownhorizontalpositionandlackofgeometricclosure.Thislackofgeometricclosuremeansthatthereisnogeometricverificationpossiblewithrespecttotheactualpositioningofthetraversestations.Thus,themeasuringtechniquemustberefinedtoprovideforfieldverification.Ataminimum,distancesaremeasuredtwiceandanglesaredoubled.Opentraversesareoftenusedforpreliminarysurveyforaroadorrailroad.
Closedtraverses,whethertheyreturntothestartingpointornot,providechecksonthemeasuredanglesanddistances.Inbothcases,theanglescanbeclosedgeometrically,andthepositionclosurecanbedeterminedmathematically.Thereforetheyaremoredesirableandusedextensivelyincontrol,construction,property,andtopographicsurveys.
angularclosure:
Thedifferencebetweenthegeometricsumandactualfieldsumoftheinterioranglesiscalledangularclosure.
latitude:
Bydefinition,latitudehereisthenorth/southrectangularcomponentofali
neanddepartureistheeast/westrectangularcomponentofaline.
Unit6MethodsofElevationDetermination
Elevation:
Anelevationisaverticaldistanceaboveorbelowareferencedatum.
MSL:
meanseallevel(MSL).MSLisassignedaverticalvalue(elevation)of0.000ftor0.000m.
Directorspiritleveling:
Directorspiritleveling,bymeasuringverticaldistancesdirectly.Directlevelingismostprecisemethodofdeterminingelevationsandtheonecommonlyused.
Indirectortrigonometricleveling:
Indirectortrigonometricleveling,bymeasuringverticalanglesandhorizontalorslopedistances.
BS:
aiscalledBacksight(BS)whichisarodreadingtakenonapointofknownelevationinordertoestablishtheelevationoftheinstrumentlineofsight.
FS:
biscalledForesight(FS)whichisarodreadingtakenonaturningpoint,benchmark,ortemporarybenchmarkinordertodetermineitselevation.
SpiritLeveling:
Themostprecisemethodofdeterminingelevationsandmostcommonlyusedmethod.Trigonometriclevelingisusedwheredifficultterrain,suchasmountainousareas,precludestheuseofconventionaldifferentialleveling.
Theimportantnotesshouldbementionedhereisthatsurveyorsusedtoworkingwithspiritlevelshavereferencedorthometricheights(H)tothe“average”surfaceoftheearth,asdepictedbyMSL.However,theelevationcoordinate(h)givenbyGPSsolutionsreferstotheheightfromthesurfaceoftheellipsoidtothegroundstation.
Unit7RoboticTotalStation
TotalS
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 测绘 工程 专业 英语 复习资料