Unit2GeodeticSurveying

andPlaneSurveyingHeNanGeologyMinaralCollegeYangLikun01GeodeticSurveyingCONTENTS目錄02PlaneSurveying03RelationbetweenGeodeticsurveyingandPlanesurveyingPARTONEGeodeticSurveying01GeodeticSurveyingThetypeofsurveyingthattakesintoaccountthetrueshapeoftheearthiscalledgeodeticsurveying.考慮地球真實形狀的測量工作稱為大地測量。Thistypeofsurveyissuitedforlargeareasandlonglinesandisusedtofindthepreciselocationofbasicpointsneededforestablishingcontrolforothersurveys.這種測量適用于大范圍和長距離的測量工作，用來確立基本點的精確位置，用以建立其他測量工作所需的控制網。GeodeticSurveyingIngeodeticsurveys,thestationsarenormallylongdistancesapart,andmorepreciseinstrumentsandsurveyingmethodsarerequiredforthistypeofsurveyingthanforplanesurveying.在大地測量中，站點經常是互相距離很遠，那么這種測量就比平面測量需要更精確的儀器和測量方法。GeodeticSurveyingWidelyspaced,permanentmonumentsserveasthebasisforcomputinglengthsanddistancesbetweenrelativepositions.

間隔很遠的永久標石就作為計算點位之間距離的基礎。GeodeticSurveyingThesebasicpointswithpermanentmonumentsarecalledgeodeticcontrolsurveypoints,whichsupporttheproductionofconsistentandcompatibledataforsurveyingandmappingprojects.這種永久標石點被稱為大地控制點，為測量和繪圖工作提供可靠和一致的數據。GeodeticSurveyingInthepast,ground-basedtheodolites,tapes,andelectronicdevicesweretheprimarygeodeticfieldmeasurementsused.過去，大地經緯儀、卷尺和電子設備是大地測量的野外工作初時的工具。GeodeticSurveyingToday,thetechnologicalexpansionofGPShasmadeitpossibletoperformextremelyaccurategeodeticsurveysatafractionofthecost.現在，技術的發展GPS使大地測量工作花費非常小的代價就能獲得極為精確的結果成為可能。擴張，擴大GeodeticSurveyingn.分數，小數；小部分，微量；Athoroughknowledgeoftheprinciplesofgeodesyisanabsoluteprerequisitefortheproperplanningandexecutionofgeodeticsurveys.大地測量工作計劃的編制和實施，絕對需要對大地測量學知識有全面的掌握。GeodeticSurveyingInGeodeticSurveys,theshapeoftheearthisthoughtofasaspheroid,althoughinatechnicalsense,itisnotreallyaspheroid（?sf??r??d，n.球狀體；）.在大地測量中，地球的形狀被看成一個橢球體，雖然在技術角度來看，它不是真正的橢球。GeodeticSurveyingTherefore,distancesmeasuredonornearthesurfaceoftheeartharenotalongstraightlinesorplanes,butonacurvedsurface.Hence,inthecomputationofdistancesingeodeticsurveys,allowancearemadefortheearth'sminorandmajordiametersfromwhichaspheroidofreferenceisdeveloped.因此，在地表或其附近所測得的距離不是直線距離或平面上的距離，而是在曲面上的距離。所以，在大地測量中計算距離時，應根據有地球長、短半軸所形成的參考橢球來設定容許差。GeodeticSurveyingThepositionofeachgeodeticstationisrelatedtothisspheroid.每個大地站點的位置都與這個橢球有關。GeodeticSurveyingThepositionsareexpressedaslatitudesandlongitudesorasnorthingsandeastingsonarectangulargrid.這個位置是用緯度和經度或用在直角坐標系中的北距和東距來表示。GeodeticSurveying

Ageodeticsurveyestablishesthefundamentalsforthedeterminationofthesurfaceandgravityfieldofacountry.大地測量為建立國家范圍內的重力場和確定地表架構提供基礎。GeodeticSurveyingThisisrealizedbycoordinatesandgravityvaluesofasufficientlylargenumberofcontrolpoints,arrangedingeodeticandgravimetricnetworks.這將由測定布設在大地網和重力網中數量十分巨大的控制點，所得到的坐標和重力值來實現。v.安排，籌備；整理，布置，排列；改編；商定GeodeticSurveyingInthisfundamentalwork,curvatureandthegravityfieldoftheearthmustbeconsidered.在這項基礎工作中，地球的曲率和重力場都應被考慮。GeodeticSurveyingPARTTWOPlaneSurveying02PlaneSurveyingThetypeofsurveyinginwhichthemeansurfaceoftheearthisconsideredaplane,orinwhichthecurvatureoftheearthcanbedisregardedwithoutsignificanterror,generallyiscalledplanesurveying.這種類型的測量把地球平均的表面視作平面，或認為地球曲率帶來的誤差可以忽略不計，這樣的測量工作稱為平面測量。Thetermisusedtodesignatesurveyworkinwhichthedistancesorareasinvolvedareoflimitedextent.這個術語曾指涉及的距離及范圍非常有限的測量工作。v.把……定名為，把……描述為；任命，指定；標明，標示PlaneSurveyingWithregardtohorizontaldistancesanddirections,alevellineisconsideredmathematicallystraight,thedirectionoftheplumblineisconsideredtobethesameatallpointswithinthelimitsofthesurvey,andallanglesareconsideredtobeplaneangles.由于被當成了水平距離和方向，水平線被當成直線，在這個有限范圍內所有點上的鉛垂線方向被認為是相同的，所有的角被認為都是平面角。

PlaneSurveyingTomakecomputationsinplanesurveying,youwilluseformulasofplanetrigonometry,algebra,andanalyticalgeometry.在平面測量的計算中，你可以使用平面三角、代數、計算中，你可以使用平面三角、代數、和平面解析幾何的公式。PlaneSurveyingForsmallareas,preciseresultsmaybeobtainedwithplanesurveyingmethods,buttheaccuracyandprecisionofsuchresultswilldecreaseastheareasurveyedincreasesinsize.小范圍內，平面測量方法可以獲得精確的結果，但是隨著范圍的擴大，精度和準確度將隨之下降。

PlaneSurveyingItwillbeappreciatedthatthecurvatureoftheearthmustbetakenintoconsiderationonlyinprecisesurveysoflargeareas.只有在大面積的精密測量工作中地球曲率才必需被考慮。

PlaneSurveyingAgreatnumberofsurveysareoftheplanesurveyingtype.多數的測量工作都是屬于平面測量類型。PlaneSurveyingSurveysforthelocationandconstructionofhighways,railroads,canals,andingeneral,thesurveysnecessaryfortheworksofhumanbeingsareplanesurveys,asarethesurveysmadetoestablishboundaries,exceptstateandnational.區域測量、公路建設、鐵路、溝渠等，總的來說與人們工作密切相關的測量工作都是平面測量，不包括州界和國界測量在內的邊界測量也同屬平面測量。PlaneSurveyingPARTTHREERelationbetweenGeodeticsurveyingandPlanesurveying03RelationbetweenGeodeticsurveyingandPlanesurveyingThereisclosecooperationbetweengeodeticsurveyingandplanesurveying.大地測量和平面測量關系密切。The