激光测距外文翻译

LaserrangefinderAlongrangelaserrangefinderiscapableofmeasuringdistanceupto20km;mountedonatripodwithanangularmount.Theresultingsystemalsoprovidesazimuthandelevationmeasurements.Alaserrangefinderisadevicewhichusesalaserbeamtodeterminethedistancetoanobject.Themostcommonformoflaserrangefinderoperatesonthetimeofflightprinciplebysendingalaserpulseinanarrowbeamtowardstheobjectandmeasuringthetimetakenbythepulsetobereflectedoffthetargetandreturnedtothesender.Duetothehighspeedoflight,thistechniqueisnotappropriateforhighprecisionsub-millimetermeasurements,wheretriangulationandothertechniquesareoftenused.PulseThepulsemaybecodedtoreducethechancethattherangefindercanbejammed.ItispossibletouseDopplereffecttechniquestojudgewhethertheobjectismovingtowardsorawayfromtherangefinder,andifsohowfast.PrecisionTheprecisionoftheinstrumentisdeterminedbytheriseorfalltimeofthelaserpulseandthespeedofthereceiver.Onethatusesverysharplaserpulsesandhasaveryfastdetectorcanrangeanobjecttowithinafewmillimeters.RangeDespitethebeambeingnarrow,itwilleventuallyspreadoverlongdistancesduetothedivergenceofthelaserbeam,aswellasduetoscintillationandbeamwandereffects,causedbythepresenceofairbubblesintheairactingaslensesranginginsizefrommicroscopictoroughlyhalftheheightofthelaserbeam'spathabovetheearth.Theseatmosphericdistortionscoupledwiththedivergenceofthelaseritselfandwithtransversewindsthatservetopushtheatmosphericheatbubbleslaterallymaycombinetomakeitdifficulttogetanaccuratereadingofthedistanceofanobject,say,beneathsometreesorbehindbushes,orevenoverlongdistancesofmorethan1kminopenandunobscureddesertterrain.Someofthelaserlightmightreflectoffleavesorbrancheswhicharecloserthantheobject,givinganearlyreturnandareadingwhichistoolow.Alternatively,overdistanceslongerthan1200ft(365m),thetarget,ifinproximitytotheearth,maysimplyvanishintoamirage,causedbytemperaturegradientsintheairinproximitytotheheatedsurfacebendingthelaserlight.Alltheseeffectshavetobetakenintoaccount.CalculationThedistance।betweenpointAandBisgivenbyD=ct/21Iwherecisthespeedoflightintheatmosphereandtistheamountoftimefortheround-tripbetweenAandB.gwhereisthedelaywhichmadebythelighttravelingand,,istheangularfrequencyofopticalmodulation.ThensubstitutethevaluesintheequationD=ct/2,D=1/2ct=1/2c/=c/(4f)()=c/4f()=U()inthisequation,Ustandsfortheunitlength.standsforthedelaypartwhichdoesnotfulfill.standsthedecimalvalue.DiscriminationSomeinstrumentsareabletodeterminemultiplereturns,asabove.Theseinstrumentsusewaveform-resolvingdetectors,whichmeanstheydetecttheamountoflightreturnedoveracertaintime,usuallyveryshort.Thewaveformfromalaserpulsethathitsatreeandthenthegroundwouldhavetwopeaks.Thefirstpeakwouldbethedistancetothetree,andthesecondwouldbethedistancetotheground.Usingwavefrontsensing,itispossibletodetermineboththeclosestandthefarthestobjectatagivenpoint.Thismakesitpossibleforaircraft-mountedinstrumentstosee"through"densecanopies[clarificationneededPleaseexplainhowlasersseethroughcanopies]andothersemi-reflectivesurfacesuchastheocean,leadingtomanyapplicationsforairborneinstrumentssuchas:Creating"bareearth"topographicmaps-removingalltreesCreatingvegetationthicknessmapsBathymetry(measuringtopographyundertheocean)ForestfirehazardTechnologiesTimeofflight-thismeasuresthetimetakenforalightpulsetotraveltothetargetandback.Withthespeedoflightknown,andanaccuratemeasurementofthetimetaken,thedistancecanbecalculated.Manypulsesarefiredsequentiallyandtheaverageresponseismostcommonlyused.Thistechniquerequiresveryaccuratesub-nanosecondtimingcircuitry.Multiplefrequencyphase-shift-thismeasuresthephaseshiftofmultiplefrequenciesonreflectionthensolvessomesimultaneousequationstogiveafinalmeasure.Interferometry-themostaccurateandmostusefultechniqueformeasuringchangesindistanceratherthanabsolutedistances.ApplicationsMilitaryAnAmericansoldierwithaGVS-5laserrangefinder.ADutchISAFsniperteamdisplayingtheirAccuracyInternationalAWSM.338LapuaMagnumrifleandLeica/VectronixVECTORIVlaserrangefinderbinoculars.Rangefindersprovideanexactdistancetotargetslocatedbeyondthedistanceofpoint-blankshootingtosnipersandartillery.Theycanalsobeusedformilitaryreconciliationandengineering.Handheldmilitaryrangefindersoperateatrangesof2kmupto25kmandarecombinedwithbinocularsormonoculars.Whentherangefinderisequippedwithadigitalmagneticcompass(DMC)andinclinometeritiscapableofprovidingmagneticazimuth,inclination,andheight(length)oftargets.Somerangefinderscanalsomeasureatarget'sspeedinrelationtotheobserver.Somerangefindershavecableorwirelessinterfacestoenablethemtotransfertheirmeasurement(s)datatootherequipmentlikefirecontrolcomputers.Somemodelsalsoofferthepossibilitytouseadd-onnightvisionmodules.Mosthandheldrangefindersusestandardorrechargeablebatteries.Themorepowerfulmodelsofrangefindersmeasuredistanceupto25kmandarenormallyinstalledeitheronatripodordirectlyonavehicleorgunplatform.Inthelattercasetherangefindermoduleisintegratedwithon-boardthermal,nightvisionanddaytimeobservationequipment.Themostadvancedmilitaryrangefinderscanbeintegratedwithcomputers.Tomakelaserrangefindersandlaser-guidedweaponslessusefulagainstmilitarytargets,variousmilitaryarmsmayhavedevelopedlaser-absorbingpaintfortheirvehicles.Regardless,someobjectsdon'treflectlaserlightverywellandusingalaserrangefinderonthemisdifficult.3-DModellingThisLIDARscannermaybeusedtoscanbuildings,rockformations,etc.,toproducea3Dmodel.TheLIDARcanaimitslaserbeaminawiderange:itsheadrotateshorizontally,amirrorflipsvertically.Thelaserbeamisusedtomeasurethedistancetothefirstobjectonitspath.Laserrangefindersareusedextensivelyin3-Dobjectrecognition,3-Dobjectmodelling,andawidevarietyofcomputervision-relatedfields.Thistechnologyconstitutestheheartoftheso-calledtime-of-flight3Dscanners.Incontrasttothemilitaryinstrumentsdescribedabove,laserrangefindersofferhigh-precisionscanningabilities,witheithersingle-faceor360-degreescanningmodes.Anumberofalgorithmshavebeendevelopedtomergetherangedataretrievedfrommultipleanglesofasingleobjecttoproducecomplete3-Dmodelswithaslittleerroraspossible.Oneoftheadvantagesthatlaserrangefindersofferoverothermethodsofcomputervisionisthatthecomputerdoesnotneedtocorrelatefeaturesfromtwoimagestodeterminedepthinformationasinstereoscopicmethods.Laserrangefindersusedincomputervisionapplicationsoftenhavedepthresolutionsoftenthsofmillimetersorless.ThiscanbeachievedbyusingtriangulationorrefractionmeasurementtechniquesasopposedtothetimeofflighttechniquesusedinLIDAR.ForestryLaserrangefinderTruPulseusedforforestinventories(incombinationwithField-Maptechnology)Speciallaserrangefindersareusedinforestry.Thesedeviceshaveanti-leaffiltersandworkwithreflectors.Laserbeamreflectsonlyfromthisreflectorandsoexactdistancemeasurementisguaranteed.Laserrangefinderswithanti-leaffilterareusedforexampleforforestinventories.SportsLaserrangefindersmaybeeffectivelyusedinvarioussportsthatrequireprecisiondistancemeasurement,suchasgolf,hunting,andarchery.Someofthemorepopularmanufacturersare:Opti-logicCorporation,Bushnell,LaserTechnology,Trimble,Leica,NewconOptik,Nikon,andSwarovskiOptik.IndustryproductionprocessesAnimportantapplicationistheuseoflaserRangefindertechnologyduringtheautomationofstockmanagementsystemsandproductionprocessesinsteelindustry.SafetyLaserrangefindersforconsumersarelaserclass1devicesandthereforeareconsideredeyesafe.Somelaserrangefindersformilitaryuseexceedthelaserclass1energylevels.HistoryDevelopmentofthemethodsusedinmodernprintedcircuitboardsstartedearlyinthe20thcentury.In1903,aGermaninventor,AlbertHanson,describedflatfoilconductorslaminatedtoaninsulatingboard,inmultiplelayers.ThomasEdisonexperimentedwithchemicalmethodsofplatingconductorsontolinenpaperin1904.ArthurBerryin1913patentedaprint-and-etchmethodinBritain,andintheUnitedStatesMaxSchoopobtainedapatent[1]toflame-spraymetalontoaboardthroughapatternedmask.CharlesDurcasein1927patentedamethodofelectroplatingcircuitpatterns.TheAustrianJewishengineerPaulEislerinventedtheprintedcircuitwhileworkinginEnglandaround1936aspartofaradioset.Around1943theUSAbegantousethetechnologyonalargescaletomakeproximityfusesforuseinWorldWarII.Afterthewar,in1948,theUSAreleasedtheinventionforcommercialuse.Printedcircuitsdidnotbecomecommonplaceinconsumerelectronicsuntilthemid-1950s,aftertheAuto-SemblyprocesswasdevelopedbytheUnitedStatesArmy.Beforeprintedcircuits(andforawhileaftertheirinvention),point-to-pointconstructionwasused.Forprototypes,orsmallproductionruns,wirewraporturretboardcanbemoreefficient.Predatingtheprintedcircuitinvention,andsimilarinspirit,wasJohnSargrove's19361947ElectronicCircuitMakingEquipment(ECME)whichsprayedmetalontoaBakeliteplasticboard.TheECMEcouldproduce3radiosperminute.DuringWorldWarII,thedevelopmentoftheanti-aircraftproximityfuserequiredanelectroniccircuitthatcouldwithstandbeingfiredfromagun,andcouldbeproducedinquantity.TheCentralabDivisionofGlobeUnionsubmittedaproposalwhichmettherequirements:aceramicplatewouldbescreenprintedwithmetallicpaintforconductorsandcarbonmaterialforresistors,withceramicdisccapacitorsandsubminiaturevacuumtubessolderedinplace.Originally,everyelectroniccomponenthadwireleads,andthePCBhadholesdrilledforeachwireofeachcomponent.Thecomponents'leadswerethenpassedthroughtheholesandsolderedtothePCBtrace.Thismethodofassemblyiscalledthrough-holeconstruction.In1949,MoeAbramsonandStanislausF.DankooftheUnitedStatesArmySignalCorpsdevelopedtheAuto-Semblyprocessinwhichcomponentleadswereinsertedintoacopperfoilinterconnectionpatternanddipsoldered.Thepatenttheyobtainedin1956wasassignedtotheU.S.Army.[4]Withthedevelopmentofboardlaminationandetchingtechniques,thisconceptevolvedintothestandardprintedcircuitboardfabricationprocessinusetoday.Solderingcouldbedoneautomaticallybypassingtheboardoveraripple,orwave,ofmoltensolderinawave-solderingmachine.However,thewiresandholesarewastefulsincedrillingholesisexpensiveandtheprotrudingwiresaremerelycutoff.Inrecentyears,theuseofsurfacemountpartshasgainedpopularityasthedemandforsmallerelectronicspackagingandgreaterfunctionalityhasgrown.激光测距仪激光测距仪是一种设备，它采用了激光束来确定对象的距离。激光测距仪的最常见的形式运行在窄光束激光脉冲通过发送对对象和测量飞行时间原则上要反映小康的目标，并退回给发件人脉冲的时间。由于高光的速度，这种技术是不为亚毫米级的测量精度高，在适当的三角和其他技术经常被用来。脉冲编码脉冲可减少测距仪可机会卡住。这是可能使用多普勒效应的技术，来判断该对象是否是朝向或远离测距仪，如果这样的速度有多快。精密该仪器的精度是由激光脉冲的上升或下降时间和接收器的速度。一个使用非常尖锐的激光脉冲，并有一个非常快的探测器范围对象几毫米之内。范围尽管是窄的光束，它最终将遍布由于长距离的激光束发散，以及由于闪烁和光束漂移的影响，由大小不等，从镜头的空气中存在气泡引起的微观到激光束的路径在地球上空大约有一半的高度。这些大气中的扭曲与激光本身的分歧，并为推动横向风，再加上大气的热气泡横向相结合，使其很难获得一个物体的距离准确的读数，说下一些树木或灌木丛背后，或什至超过开放，视野开阔的沙漠地形中超过公里长的距离。激光有些人可能会反映树叶或树枝，这是比对象更紧密，从而早日回归和阅读太低。另外，距离超过英尺(米)，如果在接近地球的目标，不再只是可能到由温度引起的海市蜃楼，在弯曲的激光加热表面附近的空气梯度消失。所有这些影响必须加以考虑。计算点和之间的距离其中是光在大气中的速度和是为和之间的往返时间哪里修光旅游和延迟g光调制角频率。然后替换值的公式：，克拉•①3(n)(n△①)(△)的ii()在这个公式中，代表单位长度。△中表示延迟部分不履行n。△代表的十进制值。歧视有些工具是能够确定多回报，如上。这些文书的使用波形，解决探测器，这意味着他们检测到的光量，在一定的时间返回，通常很短。从击中了一棵树，然后在地面的激光脉冲的波形，将有两个高峰。第一个高峰将树的距离，第二个会到地面的距离。使用波前探测，这是可能的，以确定最近和最远的物体在某一时间点。这使得机载仪器看到“通过”密集的遮篷和其他半反射的表面，如海洋，导致许多应用，如空中文书：创建“裸露”地球地形图消除所有的树木创建植被厚度地图水深（下测量地形海洋）森林火灾的危险技术飞行时间测量光脉冲的时间，前往目标和背部。与已知的光的速度，时间的精确测量，距离可以计算出来。许多脉冲发射顺序，是最常用的平均响应。这种方法需要非常精确的子纳秒级定时电路。多频相移这个测量多个频率上反射相移，然后解决了一些联立方程组，给一个最终的措施。干涉测量距离的变化，而不是绝对的距离最准确，最有用的技术。应用军事测距仪提供了一个空白点位于距离以外的目标拍摄狙击手和炮兵的精确距离。手持式军用测距仪在公里至公里范围内运作，并结合双筒望远镜或单筒望远镜。当测距仪配备数字磁罗盘（）和倾角，它是能够提供磁方位角，倾角，目标高度（长度）。还有些测距仪可以测量目标的速度，在关系到观察员。某些测距仪拥有有线或无线接口，使他们以他们的测量（）数据传输到其他设备，如消防控制计算机。有些机型还提供了可能性，使用附加的夜视模块。大多数手持测距仪使用标准或可充电电池。测距仪测量距离可达公里和更强大的模型通常安装在三脚架上，或直接上车或枪平台。在后一种情况下的测距模块集成板上热，夜视和白天的观测设备。可以与计算机集成最先进的军事测距仪。为了使激光测距仪和激光制导武器打击军事目标，各种军事武器可能已开发的激光吸收其车辆的油漆。无论如何，某些对象不反映激光非常好，对他们使用激光测距仪是困难的。建模激光测距仪被广泛使用的物体识别，三维对象建模，以及种类繁多的计算机视觉相关