《数字测图》课件-3.4.1航测影像进行野外数据采集基本知识认识

数字测图DigitalMappingBasicKnowledgeofAerialSurveyImagesforFieldDataCollection航测影像进行野外数据采集基本知识认识航测影像数据采集是指利用非接触传感器系统获得的影像及其数字表达进展记录、量测和解译，从而获得自然物体和环境的可靠信息的一门技术。Aerialphotographydatacollectionreferstothetechnologyofobtainingreliableinformationaboutnaturalobjectsandtheenvironmentbyrecording,measuring,andinterpretingimagesandtheirdigitalexpressionsobtainedusingnon-contactsensorsystems.航测影像数据采集概述OverviewofAerialImageDataAcquisition

航空摄影测量数据采集的过程中，主要是利用飞机航摄仪器对地面连续摄取像片，结合地面控制点测量、调绘和立体测绘等步骤制出地形图的作业，在保障采集相关测量数据的准确性前提下，其工作效率也有着显著的提升，尤其是外业工作量大幅降低。Intheprocessofaerialphotographymeasurementdatacollection,mainlyusingaircraftphotogrammetryequipmenttocontinuouslycaptureimagesheetsoftheground,combinedwithgroundcontrolpointmeasurement,mapping,andstereosurveyingandmappingstepstoproducetopographicmaps.Underthepremiseofensuringtheaccuracyofdatacollection,itsworkefficiencyhasalsosignificantlyimproved,especiallywithasignificantreductioninfieldwork.航测影像数据采集概述OverviewofAerialImageDataAcquisition摄影测量的野外数据采集就是通过航摄飞机、无人飞机等载体对作业区域按既定的方案进展航空摄影获取该区域的航空相片的过程。Photogrammetricfielddatacollectionreferstotheprocessofacquiringaerialphotographsofthesurveyareabyaircraft,unmannedaircraft,etc.accordingtoapredeterminedscheme.航测影像数据采集概述OverviewofAerialImageDataAcquisition0102Verticalphotogrammetry垂直摄影测量倾斜摄影测量Obliquephotogrammetry航测影像数据采集概述OverviewofAerialImageDataAcquisitionVerticalPhotogrammetry垂直摄影测量常见的垂直摄影采集使用单镜头拍照获取影像，原始影像均只是俯视图，立体信息不足，不能实时调整观察者视觉方向，不符合人眼三维浏览的习惯，获取影像为正射水平投影后的影像，尤其是在地物影像采集中，缺少建筑物立面信息和墙角准确位置信息，地物获取精度无法满足大比例尺地形图测绘需求。Verticalphotogrammetryisacommonmethodforcollectingaerialimagesusingasinglelenscameratocaptureimages.Theoriginalimagesarealljusttop-downviews,lackingstereoinformationandunabletoadjusttheviewer'svisualdirectioninrealtime,whichisnotinlinewiththehabitofviewingthree-dimensionalimageswiththehumaneye.Theobtainedimagesaretheorthophotolevelprojectionimages,especiallyinthecollectionofgroundobjectimages,lackinginformationaboutthebuildingfacadeandaccuratewallcornerpositions,andtheaccuracyofgroundobjectacquisitioncannotmeetthedemandforlarge-scaletopographicmapsurveying.ObliquePhotogrammetry倾斜摄影测量倾斜摄影测量技术是指通过在同一飞行平台上搭建5镜头相机，并从一个垂直、四个倾斜五个不同角度拍摄影像相片，同时记录航高、航速、航向以及旁边重叠坐标等参数。Obliquephotogrammetryisatechniquethatinvolvesinstallingfivecamerasonthesameflightplatformandtakingphotographsfromfivedifferentangles,includingoneverticalandfourobliqueangles,whilealsorecordingparameterssuchasflightheight,speed,anddirection,aswellasoverlappingcoordinates.ObliquePhotogrammetry倾斜摄影测量使用专业数据处理软件对影像数据进行处理后，形成的数据成果能直观反映地物的外观、位置、高度等属性，为实景三维建模或大比例尺测图、工程竣工测量提供真实的效果和测绘级精度提供保证。Usingprofessionaldataprocessingsoftware,theimagedatacanbeprocessedtoformadataresultthatcanreflecttheappearance,position,height,andotherattributesofthegroundobjects,providingrealresultsandsurveyingaccuracyfor3Dmodelingorlarge-scaletopographicmappingandengineeringcompletionmeasurement.ObliquePhotogrammetry倾斜摄影测量在大比例尺地形图数据采集中最为常见的采集模式：Themostcommoncollectionmodesinlarge-scaletopographicmapdatacollection:倾斜摄影测量三维建模数据采集无人机的分类ClassificationofUnmannedAerialVehicles按照飞机形态及架构的不同，无人机可分为：Accordingtothedifferentformsandstructuresoftheaircraft,UAVscanbedividedinto:固定翼无人机Fixed-wingUAVs旋翼无人机Rotary-wingUAVs固定翼无人机通过动力系统、机翼滑翔部件实现无人机的起飞和降落，起飞方式主要有弹射起飞和滑跑起飞两种方式，具有续航时间长、飞行效率高、载荷大的特点。Fixed-wingUAVsusepowersystemsandwingglidercomponentstoachievethetakeoffandlandingofUAVs.Thetakeoffmethodsmainlyincludecatapulttakeoffandtaxiingtakeoff.Theyhavethecharacteristicsoflongendurance,highflightefficiency,andlargeloadcapacity.Fixed-wingUAVs固定翼无人机多旋翼无人机，多旋翼无人机是由多组旋翼动力系统组成的飞行平台，它在空中飞行的升力由一个或多个旋翼旋转产生与空气进行相对运动的反作用力获得，一般常见的有四旋翼、六旋翼、八旋翼组成。Fixed-wingUAVsarecomposedofmultiplesetsofrotorpowersystemsandareusedtoprovideliftbyrotatingoneormorerotors,whichproduceareactionforcewithairrelativemotion.Commononesincludequadcopters,hexacopters,andoctocopters.多旋翼无人机MultirotorUAVs多旋翼无人机具有良好的飞行稳定性，对起飞场地要求不高，适用于起降空间狭小，任务环境复杂的场合，具备人工遥控、定点悬停、航线飞行的多种飞行模式。Fixed-wingUAVshavegoodflightstabilityandlowtake-offrequirements.Theyaresuitableforsituationswithsmalltake-offandlandingspacesandcomplexmissionenvironments.Theyhavemultipleflightmodes,includingmanualremotecontrol,fixed-pointhovering,androuteflight.MultirotorUAVs多旋翼无人机01低成本Lowcost无人机及其所使用传感器成本远远低于其他遥感系统，无人机系统（包括传感器）整体价格相对低廉，一般的单位都有能力承担。Thecostofunmannedaerialvehiclesandtheirsensorsismuchlowerthanthatofotherremotesensingsystems.TheoverallpriceoftheUAVsystem(includingsensors)isrelativelylow,andmostorganizationshavetheabilitytobearit.无人机摄影测量的特点CharacteristicsofUnmannedAerialVehiclesPhotogrammetry02影像获取快捷方便Theimageryacquisitionprocessisquickandconvenientusingdrones无需专业航测设备，普通单反相机即可作为影像获取的传感器。飞机操控手经过一定时间的操作培训即可掌握、操控整个无人机系统。这是目前唯一将摄影与测量集成在一起的航摄方式，可实现测绘单位实时按需进行航摄作业，在几十分钟之内即可获取测区的高清航测影像。It'snotnecessarytouseprofessionalaerialsurveyingequipment,andaregularsingle-lensreflexcameracanbeusedasanimagingsensor.Afteracertainperiodofoperationtraining,anaircraftoperatorcanmasterandoperatetheentireUAVsystem.Thisistheonlywaytointegratephotographyandmeasurementintoaerialphotography,whichcanallowmappingunitstoconductaerialphotographyworkinrealtimeandasneeded,andacquirehigh-resolutionaerialsurveyimageswithinafewminutes.无人机摄影测量的特点CharacteristicsofUnmannedAerialVehiclesPhotogrammetry03机动性、灵活性及安全性较高Highermaneuverability,flexibilityandsafety无人机因其自身的结构特点，无需专门的起降场地，只要在测区有一定范围的空旷、平坦、结实地块即可操作，飞控准备时间短，受空中管制和天气影响较小，特别适合于在建筑物密集地区、地貌复杂地区以及一些因特殊情况人员不能到达的地区的航测工作。Unmannedaerialvehicles(UAVs)canbeoperatedwithoutadedicatedtakeoffandlandingareaaslongasthereisacertainrangeofopen,flat,andsolidlandinthetestarea.Thepreparationtimeforflightcontrolisshort,andtheyarelessaffectedbyairtrafficcontrolandweather.Theyareparticularlysuitableforaerialsurveyinginareaswithdensebuildings,complexterrain,andspecialsituationswherepeoplecannotreach.无人机摄影测量的特点CharacteristicsofUnmannedAerialVehiclesPhotogrammetry04获取影像分辨率高Acquireimageswithhighresolution无人机低空飞行影像采集技术，有效弥补了卫星光学遥感及传统航空摄影测量经常受到高空、云层遮挡等状况导致的分辨率低、影像缺失等现象。Unmannedaerialvehicle(UAV)low-altitudeflightimagingcollectiontechnologyeffectivelycompensatesforthelowresolutionandimagemissingcausedbyhighaltitudeandcloudcoverinsatelliteopticalremotesensingandtraditionalaerialphotogrammetry.无人机摄影测量的特点CharacteristicsofUnmannedAerialVehiclesPhotogrammetry04获取影像分辨率高Acquireimageswithhighresolution同时，低空多视角倾斜摄影技术，实现多视角采集地面构筑物的多面高分辨率表面纹理数据，弥补了传统大飞机摄影测量获取城市建筑物数据时建筑物相互遮挡问题，其空间分辨率可以达到厘米级别，可用于构建高精度DEM及空间三维模型。Atthesametime,low-altitudemulti-angleobliquephotographytechnologyrealizesmulti-anglecollectionofhigh-resolutionsurfacetexturedataofgroundbuildingsfrommultipleperspectives,whichmakesupforthemutualocclusionproblemwhentraditionallargeaircraftphotogrammetryacquiresurbanbuildingdata.Itsspatialresolutioncanreachcentimeterlevel,whichcanbeusedtobuildhigh-precisiondigitalelevationmodel(DEM)andspatialthree-dimensionalmodel.无人机摄影测量的特点CharacteristicsofUnmannedAerialVehiclesPhotogrammetry05可实现大比例尺地形图绘制Unmannedaerialvehicles(UAVs)canbeusedtogeneratelarge-scaletopographicmaps其摄影测量精度地面分辨率可达到几十厘米甚至几厘米，大比例尺的测量要求。UAVphotogrammetrycanachieveagroundresolutionofseveraltensofcentimetersorevenseveralcentimeters,whichmeetsthehigh-resolutionmeasurementrequirementsoflarge-scalemaps.无人机摄影测量的特点CharacteristicsofUnmannedAerialVehiclesPhotogrammetry06工作周期短，时效性强UAVshaveashorterworkcycleandstrongertimeliness相对于常规的大比例尺地形图测量任务，可以在较短的几天时间之内，获取整个测区高分辨率的影像数据，然后将制图的工作重点转入内业，极大地提高了测绘外业作业工作效率。Comparedwithconventionallarge-scaletopographicmapmeasurementtasks,high-resolutionimagedataoftheentiresurveyareacanbeobtainedwithinafewdays,andthefocusofmappingworkcanbetransferredtotheinteriorindustry,greatlyimprovingtheefficiencyoffieldworkformapping.无人机摄影测量的特点CharacteristicsofUnmannedAerialVehiclesPhotogrammetryTheaircraft飞行器飞行器即无人机本身，是搭载摄影测量任务传感器的载体，常用的无人机平台有固定翼平台、多旋翼平台。Therootpointsonlyneedtobevisiblefromthesurveystation,makingiteasiertochoosetheoptimalpositionformapping.无人机摄影测量系统组成UAVPhotogrammetrySystemComponentsPayloadSystem荷载系统任务荷载系统主要是用于测区影像数据采集系统，常用的任务荷载设备主要有：单镜头相机、多镜头相机。Thepayloadsystemismainlyusedfortheacquisitionsystemofimagerydatainthesurveyarea.Commonpayloadequipmentincludessingle-lenscamera,multi-lenscamera.GroundControlSystem地面控制系统地面控制系统具有飞行任务规划（主要是航路规划与荷载工作规划）、任务载荷控制和数据链控制三部分。Thegroundcontrolsystemconsistsofthreeparts:flighttaskplanning(mainlyflightrouteplanningandpayloadworkplanning),payloadcontrol,anddatalinkcontrol.DataProcessingSystem数据处理系统通过数据传输，导出原始影像数据、POS数据，经影像检查后，内容数据处理软件生产DOM、DEM、DLG、高精度三维模型。Throughdatatransmission,therawimagedataandPOSdataareexported,andthenthecontentdataprocessingsoftwareproducesDOM,DEM,DLG,andhigh-precisionthree-dimensionalmodelsafterimageinspection.一项目确定、任务执行和申请空域Projectdetermination,taskexecution,andairspaceapplication测区实地踏勘，了解摄区的地理位置、地貌、地物情况、气象状况；飞行空域状况。Fieldreconnaissanceofthesurveyareatounderstandthegeographicallocation,terrain,terrainfeatures,meteorologicalconditions,andflightairspaceconditions.无人机摄影测量实施过程ImplementationProcessofUnmannedAerialVehiclePhotogrammetry二像控点的布置与测量Layoutandmeasurementofcontrolpoints像控点的布设方式和数量对模型精度是有直接的影响，一般是在测区外围和内部均匀布设像控点。Thearrangementandnumberofcontrolpointsdirectlyaffecttheaccuracyofthemodel.Ingeneral,controlpointsareevenlydistributedaroundandinsidethesurveyarea.无人机摄影测量实施过程ImplementationProcessofUnmannedAerialVehiclePhotogrammetry三航线设计、作业飞行Routedesignandflightoperation相对航高：根据项目需求所设计航摄成图比例尺的要求，依据航摄任务区域实际地貌条件及航摄影像的实际要求确定。Relativealtitude:Accordingtotherequirementsoftheprojectforthedesignofthemappingscaleoftheaerialphotography,determinetherelativealtitudeaccordingtotheactualtopographicconditionsoftheflighttaskareaandtheactualrequirementsoftheaerialphotography.无人机摄影测量实施过程ImplementationProcessofUnmannedAerialVehiclePhotogrammetry三航线设计、作业飞行Routedesignandflightoperation设置航摄影像重叠度：无人机航摄时航向重叠度在常规状况下一般设置为60%—80%，但是最小不得小于56%；旁向重叠度在常规状况下设置为30%—35%，但最小不得小于13%。而如果影像是用于倾斜建模，一般要求航向和旁向重叠度至少达到70%。Settheoverlapofaerialphotography:Innormalconditions,theoverlapofaerialphotographyinthedirectionofflightisgenerallysetto60%-80%,buttheminimumcannotbelessthan56%;theoverlapinthesidedirectionissetto30%-35%innormalconditions,buttheminimumcannotbelessthan13%.Iftheimageisusedforobliquemodeling,theoverlapofthedirectionofflightandthesidedirectionisgenerallyrequiredtobeatleast70%.无人机摄影测量实施过程ImplementationProcessofUnmannedAerialVehiclePhotogrammetry三航线设计、作业飞行Routedesignandflightoperation设置航线参数：根据项目测区大小，规划飞行任务的航向和航线距离。Setflightrouteparameters:Accordingtothesizeoftheprojectsurveyarea,plantheflightdirectionandroutedistanceoftheflighttask.无人机摄影测量实施过程ImplementationProcessofUnmannedAerialVehiclePhotogrammetry四数据检查Datacheck像片数量，是否有漏拍Thenumberofimages,whetherthereisanymissedshooting.影像清晰度、色调是否一致、层次是否明显、反差是否满足要求Theclarity,toneconsistency,layering,andcontrastoftheimageswhethermeettherequirements.观察影像是否存在阴影Whetherthereareshadowsintheimages.无人机摄影测量实施过程ImplementationProcessofUnmannedAerialVehiclePhotogrammetry四数据检查Datacheck因构筑物颜色或玻璃面积过多导致的大范围反光Large-scalereflectionduetotoomanycolorsorglassareasofbuildings.地物点模糊等突出问题Fuzzygroundobjectpoints,etc.评价模型的质量Evaluatethequalityofthemodel.无人机摄影测量实施过程ImplementationProcessofUnmannedAerialVehiclePhotogrammetry五影像处理与建模I