上海大学通信学院复试专业课英语

TechnicalEnglishForInformationScienceandElectronicEngineering0Unit15RemoteSensing1PartIAnOverviewofRemoteSensing2NewWordstether拴，束缚topographic地形的，地形学的novelty新奇，新鲜事物reconnaissance侦察oblique倾斜的perspective透视图，透视的emergence出现Earth-orbiting绕地球轨道运转的astronaut宇航员emit放射，射出categorize分类photon光子analogous类似的viceversa反之亦然accelerate加速descriptive描述性的ultraviolet紫外线，紫外的nanometer纳米（10

9m）micrometer微米（10

6m）infrared红外线，红外的3NewWordsvapor汽，蒸汽ozone臭氧transparent透明的tune调谐line-of-sight视线radiant辐射的meteorological气象的opaque不透明的impede妨碍，阻止vegetation植物decimal十进制的ingredient成分，因素informative提供消息的tint色彩discern辨别，看清楚radiometer辐射计quantitatively定量地imagingradiometer辐射成像仪spectrometer分光光度计grating光栅4NewWordsprism棱镜spectroradiometer

分光光谱仪resolution分辨率trace痕迹、微量species种，类scatterometer

散射计lidar

激光雷达aerosol烟，雾constituent成分altimeter高度计51Thetechnologyofmodernremotesensingbeganwiththeinventionofthecameramorethan150yearsago.Althoughthefirst,ratherprimitivephotographsweretakenas“stills”ontheground,theideaandpracticeoflookingdownattheEarth’ssurfaceemergedinthe1840swhenpicturesweretakenfromcamerassecuredtotetheredballoonsforpurposesoftopographicmapping.19世纪40年代，为了绘制地形图，当照相机被放在系留气球上来拍摄照片，俯视地球表面的想法和实践开始了61Perhapsthemostnovelplatformattheendofthe19thcenturyisthefamedpigeonfleetthatoperatedasanoveltyinEurope.ByWorldWarI,camerasmountedonairplanesprovidedaerialviewsoffairlylargesurfaceareasthatprovedinvaluableinmilitaryreconnaissance.Fromthenuntiltheearly1960s,theaerialphotographremainedthesinglestandardtoolfordepictingthesurfacefromaverticalorobliqueperspective.72Satelliteremotesensingcanbetracedtotheearlydaysofthespaceageandactuallybeganasadualapproachtoimagingsurfacesusingseveraltypesofsensorsfromspacecraft.Withtheemergenceofthespaceprograminthe1960s,Earth-orbitingastronautsactedmuchliketouristsbytakingphotosoutthewindowoftheirspacecraft.83Theterm“remotesensing”isnowcommonlyusedtodescribethescience,andart,ofidentifying,observing,andmeasuringanobjectwithoutcomingintodirectcontactwithit.Thisprocessinvolvesthedetectionandmeasurementofradiationofdifferentwavelengthsreflectedoremittedfromdistantobjects,bywhichtheobjectsmaybeidentifiedandcategorizedbyclass,substance,andspatialdistribution.1这一过程包含检测和测量从远处目标反射回来或发射出来的不同波长的辐射，由这些辐射，可按种类、物质、空间分布对目标进行识别和分类。94RadiationUnlessithasatemperatureofabsolutezero(

273

C)anobjectreflects,absorbs,andemitsenergyinauniqueway,andatalltimes.Thisenergy,calledelectromagnetic(EM)radiation,isemittedinwavesthatareabletotransmitenergyfromoneplacetoanother.104Forexample,trees,air,theSun,theEarth,andallthestarsandplanetsarereflectingandemittingawiderangeofelectromagneticwaves.Thesewavesoriginatefrombillionsofvibratingelectrons,atoms,andmolecules,whichemitandabsorbelectromagneticradiationinuniquecombinationsofwavelengths.2

这些波是由亿万个振动的电子、原子、分子发出的，它们以独特的波长组合发出和吸收电磁辐射。114Theamountofelectromagneticradiationanobjectemitsdependsprimarilyonitstemperature.Thehigherthetemperatureofanobject,thefasteritselectronsvibrateandtheshorteritspeakwavelengthofemittedradiation.125ElectromagneticspectrumThefundamentalunitofelectromagneticphenomenaisthephoton,thesmallestpossibleamountofelectromagneticenergyofaparticularwavelength.Photons,whicharewithoutmass,moveatthespeedoflight–300,000km/secintheformofwavesanalogoustothewaywavespropagatethroughtheoceans.独个光子能以波的形式运动，速度可达光速300,000km/sec，就像波浪在海洋中传播一样。135Theenergyofaphotondeterminesthefrequencyoflight.Thegreatertheenergyofthephoton,thegreaterthefrequencyoflight,andviceversa146TheentirearrayofelectromagneticwavescomprisestheEMspectrum.Thewavesarecalledelectromagneticbecausetheyconsistofcombinedelectricandmagneticwavesthatresultwhenachargedparticle(electron)accelerates.TheEMspectrumisdividedintoregionswithdescriptivenames.156Atthehighfrequencyendaregammaraysandx-rays.Radiationintheultravioletregionextendsfromabout1nanometertoabout0.36micrometers.Itisconvenienttomeasurethemid-regionsofthespectruminthesetwounits:micrometers(mm),aunitoflengthequivalenttoone-millionthofameter,ornanometers(nm),aunitoflengthequivalenttoone-billionthofameter.166Thevisibleregionoccupiestherangebetween0.4and0.7mm.Theinfrared(IR)regionspansbetween0.7and100mm.Atshorterwavelengths(near0.7mm)infraredradiationcanbedetectedbyspecialfilm,whileatlongerwavelengthsitisfeltasheat.177Longerwavelengthintervalsaremeasuredinunitsrangingfrommillimeters(mm)throughmeters(m).Themicrowaveregionspreadsacross1mmto1m;thisincludesalloftheintervalsusedbyradarsystems,whichgeneratetheirownactiveradiationdirectedtowardsandreflectedfromtargetsofinterest.Thelowestfrequencyregion–beyond1m–isassociatedwithradiowaves.雷达系统自己主动产生辐射，发射到感兴趣目标并从感兴趣目标反射回来。188AbsorptionbandsandatmosphericwindowsSometypesofelectromagneticradiationeasilypassthroughtheatmosphere,whileothersdonot.Theabilityoftheatmospheretoallowradiationtopassthroughvarieswiththewavelength/typeoftheradiation.Thegasesthatcompriseouratmosphereabsorbradiationincertainwavelengthswhileallowingradiationwithdifferingwavelengthstopassthrough.199TheareasoftheEMspectrumthatareabsorbedbyatmosphericgasessuchaswatervapor,carbondioxide,andozoneareknownasabsorptionbands.Absorptionbandshavealowtransmissionvalueassociatedwithaspecificrangeofwavelengths.能够被水蒸汽，二氧化碳和臭氧等大气层气体吸收的电磁波谱区域称为吸收带。2010Incontrasttotheabsorptionbands,thereareareasoftheelectromagneticspectrumwheretheatmosphereistransparenttospecificwavelengths.Thesewavelengthbandsareknownasatmospheric“windows”sincetheyallowtheradiationtoeasilypassthroughtheatmospheretoEarth’ssurface.2111Mostremotesensinginstrumentsonaircraftorspace-basedplatformsoperateinoneormoreofthesewindowsbymakingtheirmeasurementswithdetectorstunedtospecificfrequencies(wavelengths)thatpassthroughtheatmosphere.3大多数装在飞机或太空平台上的遥感仪器工作在一个或多个这样的“窗口”范围里，这是通过将其检测装置调谐在能穿透大气层的特定频率（波长）上而实现的。2211Whenaremotesensinginstrumenthasaline-of-sightwithanobjectthatisreflectingsunlightoremittingheat,theinstrumentcollectsandrecordstheradiantenergy.Whilemostremotesensingsystemsaredesignedtocollectreflectedradiation,somesensors,especiallythoseonmeteorologicalsatellites,directlymeasureabsorptionphenomena.2311TheatmosphereisnearlyopaquetoEMradiationinpartofthemid-IRandallofthefar-IRregions.Inthemicrowaveregion,bycontrast,mostofthisradiationmovesthroughunimpeded,soradarwavesreachthesurface.2412Pixels,bits,andcolorUsingradiowaves,datafromEarth-orbitingsatellitesaretransmittedonaregularbasistoproperlyequippedgroundstations.Asthedataarereceivedtheyaretranslatedintoadigitalimagethatcanbedisplayedonacomputerscreen.Satelliteimageryismadeupoftinysquares,eachofadifferentgrayshadeorcolor.Thesesquaresarecalledpixelsandrepresenttherelativereflectedlightenergyrecordedforthatpartoftheimage.2513Eachpixelrepresentsasquareareaonanimagethatisameasureofthesensor’sabilitytoresolveobjectsofdifferentsizes.Forexample,theEnhancedThematicMapperontheLandsat7satellitehasamaximumresolutionof15meters;therefore,eachpixelrepresentsanarea15m

15m,or225m2.Higherresolutionmeansthatthesensorisabletodiscernsmallerobjects.Byaddingupthenumberofpixelsinanimage,youcancalculatetheareaofascene.Forexample,ifyoucountthenumberofgreenpixelsinafalsecolorimage,youcancalculatethetotalareacoveredwithvegetation.2614Spacecraftsuseastringof8binarynumbers,whichcanrangefrom00000000to11111111(0to255inthedecimalsystem).With8-bitdata,wecanassignthedarkestpointinanimageto0,andthebrightestpointintheimageto255.Thisproduces256shadesofgraybetweenblackandwhite.Itisthesebinarynumbersthatthespacecraftsendsbackforeachpixelineveryrowandcolumn–andittakesacomputertokeeptrackofeverynumberforeverypixel.2715Anotheressentialingredientinmostremotesensingimagesiscolor.Whilevariationsinblackandwhiteimagerycanbeveryinformative,thenumberofdifferentgraytonesthattheeyecanseparateislimitedtoabout20to30steps.Ontheotherhand,theeyecandistinguish20,000ormorecolortints,enablingsmallbutoftenimportantvariationswithinthetargetmaterialsorclassestobediscerned.2816Sincedifferentbands(orwavelengths)haveadifferentcontrast,computerscanbeusedtoproduceacolorimagefromablackandwhiteremotesensingdataset.Computerscreenscandisplaythreedifferentimagesusingbluelight,greenlightandredlight.Thecombinationofthesethreewavelengthsoflightwillgeneratethecolorimagethatoureyescansee.2916Thisisaccomplishedbydisplayingblackandwhitesatelliteimagescorrespondingtovariousbandsineitherblue,green,orredlighttoachievetherelativecontrastbetweenthebands.Finally,whenthesethreecolorsarecombined,acolorimage–calledafalsecolorimage–isproduced.3017RemotesensingmethodsTherearetwotypesofremotesensinginstruments–passiveandactive.3118Passiveinstrumentsdetectnaturalenergythatisreflectedoremittedfromtheobservedscene.Passiveinstrumentssenseonlyradiationemittedbytheobjectbeingviewedorreflectedbytheobjectfromasourceotherthantheinstrument.Reflectedsunlightisthemostcommonexternalsourceofradiationsensedbypassiveinstruments.Scientistsuseavarietyofpassiveremotesensors.被动仪器只感知被观测物体发出的辐射或来自某个源而不是仪器的被物体反射的辐射32191.Radiometer:Aninstrumentthatquantitativelymeasurestheintensityofelectromagneticradiationinsomebandofwavelengthsinthespectrum.Usuallyaradiometerisfurtheridentifiedbytheportionofthespectrumitcovers;forexample,visible,infrared,ormicrowave.4

辐射计通常又按其覆盖的频谱范围来区分，例如可见光、红外、微波。33202.ImagingRadiometer:Aradiometerthatincludesascanningcapabilitytoprovideatwo-dimensionalarrayofpixelsfromwhichanimagemaybeproducediscalledanimagingradiometer.Scanningcanbeperformedmechanicallyorelectronicallybyusinganarrayofdetectors.34213.Spectrometer:Adevicedesignedtodetect,measure,andanalyzethespectralcontentoftheincidentelectromagneticradiationiscalledaspectrometer.Conventionally,imagingspectrometersusegratingsorprismstodispersetheradiationforspectraldiscrimination.35224.Spectroradiometer:Aradiometerthatcanmeasuretheintensityofradiationinmultiplewavelengthbands.Oftentimesthebandsareofahighspectralresolution–designedfortheremotesensingofspecificparameterssuchasseasurfacetemperature,cloudcharacteristics,oceancolor,vegetation,tracechemicalspeciesintheatmosphere,etc.5

这些频带经常具有高分辨率，是为特定参数的遥感而设计的，如海面温度、云地特性、植被、大气层的微量化学成分等。3623Activeinstrumentsprovidetheirownenergy(EMradiation)toilluminatetheobjectorscenetheyobserve.6主动仪器提供自己的能量（电磁辐射）来照射要观察的对象或场景。3723Theysendapulseofenergyfromthesensortotheobjectandthenreceivetheradiationthatisreflectedorbackscatteredfromthatobject.Scientistsusemanydifferenttypesofactiveremotesensors.38241.Radar(RadioDetectionandRanging):Radarusesatransmitteroperatingateitherradioormicrowavefrequenciestoemitelectromagneticradiationandadirectionalantennaorreceivertomeasurethetimeofarrivalofreflectedorbackscattredpulsesofradiationfromdistantobjects.7Distancetotheobjectcanbedeterminedsinceelectromagneticradiationpropagatesatthespeedoflight.雷达用一个工作在射频或微波频率的发射机来发出电磁辐射，用一个方向性天线或接收器来测量从远处目标反射或反向散射回来的辐射脉冲的到达时间。39252.Scatterometer:Ascatterometerisahighfrequencymicrowaveradardesignedspecificallytomeasurebackscatteredradiation.Overoceansurfaces,measurementsofbackscatteredradiationinthemicrowavespectralregioncanbeusedtoderivemapsofsurfacewindspeedanddirection.40263.Lidar(LightDetectionandRanging):Alidarusesalasertotransmitalightpulseandareceiverwithsensitivedetectorstomeasurethebackscatteredorreflectedlight.Distancetotheobjectisdeterminedbyrecordingthetimebetweenthetransmittedandbackscatteredpulsesandusingthespeedoflighttocalculatethedistancetraveled.Lidarscandetermineatmosphericprofilesofaerosols,clouds,andotherconstituentsoftheatmosphere.41274.LaserAltimeter:Alaseraltimeterusesalidartomeasuretheheightoftheinstrumentplatformabovethesurface.ByindependentlyknowingtheheightoftheplatformwithrespecttothemeanEarth’ssurface,thetopographyoftheunderlyingsurfacecanbedetermined.42PartIIUsingRemoteSensingtoMonitorGlobalChange43NewWordsinduce感应，遭致wetland湿地hydrologic水文的regime政权，体制，情态marsh沼泽，湿地swamp沼泽，进退两难之地mangrove红树fringe加边，加饰边nutrient营养habitat栖息地fur-bearinganimal毛皮动物buffer缓冲erosion腐蚀，侵蚀canal运河，沟渠diversion转移sediment沉淀物，沉积levee大堤compound复合eustatic

（全球）海面升降的predominant占主导地位的44NewWordspertinent相关的，切题的scenario情节，剧本，方案outpace赶过，超越hydrology水文学drainage排水dynamics动力学salinity盐度zonation

成带，分区linkage联合，结合thematic题目的，主旋律的monotypic单型的portrayal描绘，肖像biomass生物量responsive应答的，回答的inundation洪水，大水contour等高线elevationcontour海拔等高线quadrangle四边形standarddeviation标准差moisture湿气，水份451Toproperlyrespondtonaturalandhuman-inducedstressestowetlands,resourcemanagersmustconsidertheirfunctionsandvalues.Remotesensingisanimportanttoolformonitoringwetlandresponsestochangesinthehydrologicregimeandwaterqualitycausedbyglobalclimatechangeandsea-levelrise.监控湿地对于全球气候变化和海平面上升造成的在水文情势和水质方面的变化的反应462Extensivemarshes,swamps,andmangroveforestsfringemostoftheU.S.coastline.Besidesbeinganimportantsourceofnutrients,coastalwetlandsarenurseriesforfishandshrimpandhabitatformanybirdsandfur-bearinganimals.Theyarealsovitaltocoastalrecreation,maintainwaterquality,andserveasabufferagainstshoreerosion.1

它们对沿海休闲也是重要的，并且能保持水质，成为防止海岸侵蚀的屏障。473IntheUnitedStates,widespreadwetlandlosshasresultedfromthefillingofmarshlands,constructionofcanalsandwaterways,anddiversionofriversedimentsoffshore.2在美国，湿地萎缩是由沼泽的填充，开挖水渠、河道，河流淤泥向海面转移造成的。483Soilconservationpracticesandflood-controlstructuressuchasdamsandleveesarepreventingsedimentsfromreachingwetlands.Furthercompoundingthesehuman-inducedstresses,theeustaticsea-levelrisehasseriousimplicationsforcoastalwetlands.Predominantly,thesealevelisrisinggloballyfrom1mmto2mmyearly;however,increasingratesarepredictedtocauseabouta50cmriseinsealevelbytheyear2100.493Theseproblemsareespeciallypertinenttocoastalwetlandswheretherateofelevationrisemayonlybeabout10cmforeachkilometertraversedinland.Ifthegreenhouseeffectisconfirmedaspartoftheglobalclimatechangescenario,eventheselevelswillbeoutpaced.3

这些问题特别切合于海岸湿地，在那里横跨内陆每一公里的海拔高度上升可能只有10厘米。如果温室效应被证实是全球气候变化的部分原因，还要超出这些（上升的）水平。504Coastalhydrologyisdominatedbysurfacetopography,surfacedrainage,soilcharacter,andlocaltidaldynamics.Withanincreasingrateofsea-levelrise,tidaldynamicswilldominatethehydrologychangeswithinlow-lyingcoastalwetlands.海岸水文地理学受控于表面形貌学，地表水系，土壤特征和本地潮汐动态学。514Impactstothesewetlandswillincludechangesinsoilsalinitylevels,floodingdurationandfrequency,andwaterquality.Forecastsofhowthesechangeswillaffectthepresentandfuturewetlandspecieszonationareneeded.Tomaketheseforecasts,itisnecessarytofirstidentifytherelationshipbetweenwetlandtypeandhydrology..524RemotesensingstudiesconductedbyUSGSscientistsfocusedonintegratingground-basedandsatellitemeasurementstodeveloptoolsformeasuringandmonitoringfactorscriticaltodeterminingtheselinkages.4美国地理调查局科学家们所进行的遥感研究集中于将地面和卫星测量结合起来，开发测量和监视对确定这些联系极为重要的工具。534Theyalsodevelopedtechniquesforgeneratingcoastaltopographytosimulatefuturewetlandchangesbasedonuncoveredlinkagesandsea-levelrisescenarios545Wetlandtypes

AprogressiveclassificationofamarshandforestsystemcombiningdatafromLandsatThematicMapper(TM),colorinfraredphotography,andERS-1satelliteradarwasdevelopedthatimprovedclassificationaccuracyandresultedinadetailedidentificationofdifferenceswithinanearlymonotypicblackmarshinFlorida.5结合从LandsatTM卫星、彩色红外照片、ERS-1卫星雷达上获取的数据，构建了沼泽和森林体系的累进分类，改进了分类精度，导致佛罗里达州几乎单一黑色的沼泽地中有差异地区的细致区分。555Thesetypesofimprovementsinclassifyingcoastallandcoversarenecessarybeforeanaccurateportrayalofthelinkbetweenvegetationcharacteristicsandhydrologycanbemade.566VegetationbiomassVegetationindexesrelatedtobiomassmeasuresweregeneratedfrompassivemicrowavedataandLandsatTMdata.TheopticalTMvegetationindexbasedonredandnear-infraredwavelengthsisprimarilylinkedtochangesingreenbiomass.576Themicrowavevegetationindexbasedonmeasuringenergyemittedat6cmand21cmmicrowavewavelengthsisprimarilyresponsivetothevegetationwatercontent.Theimagesarenoticeablysimilar.Ifthemicrowaveinstrumentprovestobeanadequateestimatorofbiomassinthesewetlands,amonitoringprogramcouldbedevelopedaroundthisall-weather,day-and-nightsensor.587MonitoringfloodingSatelliteradarwasusedtomaptidalflooding,acriticalcontrolofcoastalvegetationdistribution.Radarimagestakenduringatimeofnear-continuousrecordingsofgroundbas