上海大學(xué)通信學(xué)院復(fù)試專業(yè)課英語

TechnicalEnglishForInformationScienceandElectronicEngineering0Unit15RemoteSensing1PartIAnOverviewofRemoteSensing2NewWordstether拴，束縛topographic地形的，地形學(xué)的novelty新奇，新鮮事物reconnaissance偵察oblique傾斜的perspective透視圖，透視的emergence出現(xiàn)Earth-orbiting繞地球軌道運(yùn)轉(zhuǎn)的astronaut宇航員emit放射，射出categorize分類photon光子analogous類似的viceversa反之亦然accelerate加速descriptive描述性的ultraviolet紫外線，紫外的nanometer納米（10

9m）micrometer微米（10

6m）infrared紅外線，紅外的3NewWordsvapor汽，蒸汽ozone臭氧transparent透明的tune調(diào)諧line-of-sight視線radiant輻射的meteorological氣象的opaque不透明的impede妨礙，阻止vegetation植物decimal十進(jìn)制的ingredient成分，因素informative提供消息的tint色彩discern辨別，看清楚radiometer輻射計(jì)quantitatively定量地imagingradiometer輻射成像儀spectrometer分光光度計(jì)grating光柵4NewWordsprism棱鏡spectroradiometer

分光光譜儀resolution分辨率trace痕跡、微量species種，類scatterometer

散射計(jì)lidar

激光雷達(dá)aerosol煙，霧constituent成分altimeter高度計(jì)51Thetechnologyofmodernremotesensingbeganwiththeinventionofthecameramorethan150yearsago.Althoughthefirst,ratherprimitivephotographsweretakenas“stills”ontheground,theideaandpracticeoflookingdownattheEarth’ssurfaceemergedinthe1840swhenpicturesweretakenfromcamerassecuredtotetheredballoonsforpurposesoftopographicmapping.19世紀(jì)40年代，為了繪制地形圖，當(dāng)照相機(jī)被放在系留氣球上來拍攝照片，俯視地球表面的想法和實(shí)踐開始了61Perhapsthemostnovelplatformattheendofthe19thcenturyisthefamedpigeonfleetthatoperatedasanoveltyinEurope.ByWorldWarI,camerasmountedonairplanesprovidedaerialviewsoffairlylargesurfaceareasthatprovedinvaluableinmilitaryreconnaissance.Fromthenuntiltheearly1960s,theaerialphotographremainedthesinglestandardtoolfordepictingthesurfacefromaverticalorobliqueperspective.72Satelliteremotesensingcanbetracedtotheearlydaysofthespaceageandactuallybeganasadualapproachtoimagingsurfacesusingseveraltypesofsensorsfromspacecraft.Withtheemergenceofthespaceprograminthe1960s,Earth-orbitingastronautsactedmuchliketouristsbytakingphotosoutthewindowoftheirspacecraft.83Theterm“remotesensing”isnowcommonlyusedtodescribethescience,andart,ofidentifying,observing,andmeasuringanobjectwithoutcomingintodirectcontactwithit.Thisprocessinvolvesthedetectionandmeasurementofradiationofdifferentwavelengthsreflectedoremittedfromdistantobjects,bywhichtheobjectsmaybeidentifiedandcategorizedbyclass,substance,andspatialdistribution.1這一過程包含檢測(cè)和測(cè)量從遠(yuǎn)處目標(biāo)反射回來或發(fā)射出來的不同波長(zhǎng)的輻射，由這些輻射，可按種類、物質(zhì)、空間分布對(duì)目標(biāo)進(jìn)行識(shí)別和分類。94RadiationUnlessithasatemperatureofabsolutezero(

273

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

這些波是由億萬個(gè)振動(dòng)的電子、原子、分子發(fā)出的，它們以獨(dú)特的波長(zhǎng)組合發(fā)出和吸收電磁輻射。114Theamountofelectromagneticradiationanobjectemitsdependsprimarilyonitstemperature.Thehigherthetemperatureofanobject,thefasteritselectronsvibrateandtheshorteritspeakwavelengthofemittedradiation.125ElectromagneticspectrumThefundamentalunitofelectromagneticphenomenaisthephoton,thesmallestpossibleamountofelectromagneticenergyofaparticularwavelength.Photons,whicharewithoutmass,moveatthespeedoflight–300,000km/secintheformofwavesanalogoustothewaywavespropagatethroughtheoceans.獨(dú)個(gè)光子能以波的形式運(yùn)動(dòng)，速度可達(dá)光速300,000km/sec，就像波浪在海洋中傳播一樣。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.雷達(dá)系統(tǒng)自己主動(dòng)產(chǎn)生輻射，發(fā)射到感興趣目標(biāo)并從感興趣目標(biāo)反射回來。188AbsorptionbandsandatmosphericwindowsSometypesofelectromagneticradiationeasilypassthroughtheatmosphere,whileothersdonot.Theabilityoftheatmospheretoallowradiationtopassthroughvarieswiththewavelength/typeoftheradiation.Thegasesthatcompriseouratmosphereabsorbradiationincertainwavelengthswhileallowingradiationwithdifferingwavelengthstopassthrough.199TheareasoftheEMspectrumthatareabsorbedbyatmosphericgasessuchaswatervapor,carbondioxide,andozoneareknownasabsorptionbands.Absorptionbandshavealowtransmissionvalueassociatedwithaspecificrangeofwavelengths.能夠被水蒸汽，二氧化碳和臭氧等大氣層氣體吸收的電磁波譜區(qū)域稱為吸收帶。2010Incontrasttotheabsorptionbands,thereareareasoftheelectromagneticspectrumwheretheatmosphereistransparenttospecificwavelengths.Thesewavelengthbandsareknownasatmospheric“windows”sincetheyallowtheradiationtoeasilypassthroughtheatmospheretoEarth’ssurface.2111Mostremotesensinginstrumentsonaircraftorspace-basedplatformsoperateinoneormoreofthesewindowsbymakingtheirmeasurementswithdetectorstunedtospecificfrequencies(wavelengths)thatpassthroughtheatmosphere.3大多數(shù)裝在飛機(jī)或太空平臺(tái)上的遙感儀器工作在一個(gè)或多個(gè)這樣的“窗口”范圍里，這是通過將其檢測(cè)裝置調(diào)諧在能穿透大氣層的特定頻率（波長(zhǎng)）上而實(shí)現(xiàn)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.被動(dòng)儀器只感知被觀測(cè)物體發(fā)出的輻射或來自某個(gè)源而不是儀器的被物體反射的輻射32191.Radiometer:Aninstrumentthatquantitativelymeasurestheintensityofelectromagneticradiationinsomebandofwavelengthsinthespectrum.Usuallyaradiometerisfurtheridentifiedbytheportionofthespectrumitcovers;forexample,visible,infrared,ormicrowave.4

輻射計(jì)通常又按其覆蓋的頻譜范圍來區(qū)分，例如可見光、紅外、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

這些頻帶經(jīng)常具有高分辨率，是為特定參數(shù)的遙感而設(shè)計(jì)的，如海面溫度、云地特性、植被、大氣層的微量化學(xué)成分等。3623Activeinstrumentsprovidetheirownenergy(EMradiation)toilluminatetheobjectorscenetheyobserve.6主動(dòng)儀器提供自己的能量（電磁輻射）來照射要觀察的對(duì)象或場(chǎng)景。3723Theysendapulseofenergyfromthesensortotheobjectandthenreceivetheradiationthatisreflectedorbackscatteredfromthatobject.Scientistsusemanydifferenttypesofactiveremotesensors.38241.Radar(RadioDetectionandRanging):Radarusesatransmitteroperatingateitherradioormicrowavefrequenciestoemitelectromagneticradiationandadirectionalantennaorreceivertomeasurethetimeofarrivalofreflectedorbackscattredpulsesofradiationfromdistantobjects.7Distancetotheobjectcanbedeterminedsinceelectromagneticradiationpropagatesatthespeedoflight.雷達(dá)用一個(gè)工作在射頻或微波頻率的發(fā)射機(jī)來發(fā)出電磁輻射，用一個(gè)方向性天線或接收器來測(cè)量從遠(yuǎn)處目標(biāo)反射或反向散射回來的輻射脈沖的到達(dá)時(shí)間。39252.Scatterometer:Ascatterometerisahighfrequencymicrowaveradardesignedspecificallytomeasurebackscatteredradiation.Overoceansurfaces,measurementsofbackscatteredradiationinthemicrowavespectralregioncanbeusedtoderivemapsofsurfacewindspeedanddirection.40263.Lidar(LightDetectionandRanging):Alidarusesalasertotransmitalightpulseandareceiverwithsensitivedetectorstomeasurethebackscatteredorreflectedlight.Distancetotheobjectisdeterminedbyrecordingthetimebetweenthetransmittedandbackscatteredpulsesandusingthespeedoflighttocalculatethedistancetraveled.Lidarscandetermineatmosphericprofilesofaerosols,clouds,andotherconstituentsoftheatmosphere.41274.LaserAltimeter:Alaseraltimeterusesalidartomeasuretheheightoftheinstrumentplatformabovethesurface.ByindependentlyknowingtheheightoftheplatformwithrespecttothemeanEarth’ssurface,thetopographyoftheunderlyingsurfacecanbedetermined.42PartIIUsingRemoteSensingtoMonitorGlobalChange43NewWordsinduce感應(yīng)，遭致wetland濕地hydrologic水文的regime政權(quán)，體制，情態(tài)marsh沼澤，濕地swamp沼澤，進(jìn)退兩難之地mangrove紅樹fringe加邊，加飾邊nutrient營(yíng)養(yǎng)habitat棲息地fur-bearinganimal毛皮動(dòng)物buffer緩沖erosion腐蝕，侵蝕canal運(yùn)河，溝渠diversion轉(zhuǎn)移sediment沉淀物，沉積levee大堤compound復(fù)合eustatic

（全球）海面升降的predominant占主導(dǎo)地位的44NewWordspertinent相關(guān)的，切題的scenario情節(jié)，劇本，方案outpace趕過，超越hydrology水文學(xué)drainage排水dynamics動(dòng)力學(xué)salinity鹽度zonation

成帶，分區(qū)linkage聯(lián)合，結(jié)合thematic題目的，主旋律的monotypic單型的portrayal描繪，肖像biomass生物量responsive應(yīng)答的，回答的inundation洪水，大水contour等高線elevationcontour海拔等高線quadrangle四邊形standarddeviation標(biāo)準(zhǔn)差moisture濕氣，水份451Toproperlyrespondtonaturalandhuman-inducedstressestowetlands,resourcemanagersmustconsidertheirfunctionsandvalues.Remotesensingisanimportanttoolformonitoringwetlandresponsestochangesinthehydrologicregimeandwaterqualitycausedbyglobalclimatechangeandsea-levelrise.監(jiān)控濕地對(duì)于全球氣候變化和海平面上升造成的在水文情勢(shì)和水質(zhì)方面的變化的反應(yīng)462Extensivemarshes,swamps,andmangroveforestsfringemostoftheU.S.coastline.Besidesbeinganimportantsourceofnutrients,coastalwetlandsarenurseriesforfishandshrimpandhabitatformanybirdsandfur-bearinganimals.Theyarealsovitaltocoastalrecreation,maintainwaterquality,andserveasabufferagainstshoreerosion.1

它們對(duì)沿海休閑也是重要的，并且能保持水質(zhì)，成為防止海岸侵蝕的屏障。473IntheUnitedStates,widespreadwetlandlosshasresultedfromthefillingofmarshlands,constructionofcanalsandwaterways,anddiversionofriversedimentsoffshore.2在美國(guó)，濕地萎縮是由沼澤的填充，開挖水渠、河道，河流淤泥向海面轉(zhuǎn)移造成的。483Soilconservationpracticesandflood-controlstructuressuchasdamsandleveesarepreventingsedimentsfromreachingwetlands.Furthercompoundingthesehuman-inducedstresses,theeustaticsea-levelrisehasseriousimplicationsforcoastalwetlands.Predominantly,thesealevelisrisinggloballyfrom1mmto2mmyearly;however,increasingratesarepredictedtocauseabouta50cmriseinsealevelbytheyear2100.493Theseproblemsareespeciallypertinenttocoastalwetlandswheretherateofelevationrisemayonlybeabout10cmforeachkilometertraversedinland.Ifthegreenhouseeffectisconfirmedaspartoftheglobalclimatechangescenario,eventheselevelswillbeoutpaced.3

這些問題特別切合于海岸濕地，在那里橫跨內(nèi)陸每一公里的海拔高度上升可能只有10厘米。如果溫室效應(yīng)被證實(shí)是全球氣候變化的部分原因，還要超出這些（上升的）水平。504Coastalhydrologyisdominatedbysurfacetopography,surfacedrainage,soilcharacter,andlocaltidaldynamics.Withanincreasingrateofsea-levelrise,tidaldynamicswilldominatethehydrologychangeswithinlow-lyingcoastalwetlands.海岸水文地理學(xué)受控于表面形貌學(xué)，地表水系，土壤特征和本地潮汐動(dòng)態(tài)學(xué)。514Impactstothesewetlandswillincludechangesinsoilsalinitylevels,floodingdurationandfrequency,andwaterquality.Forecastsofhowthesechangeswillaffectthepresentandfuturewetlandspecieszonationareneeded.Tomaketheseforecasts,itisnecessarytofirstidentifytherelationshipbetweenwetlandtypeandhydrology..524RemotesensingstudiesconductedbyUSGSscientistsfocusedonintegratingground-basedandsatellitemeasurementstodeveloptoolsformeasuringandmonitoringfactorscriticaltodeterminingtheselinkages.4美國(guó)地理調(diào)查局科學(xué)家們所進(jìn)行的遙感研究集中于將地面和衛(wèi)星測(cè)量結(jié)合起來，開發(fā)測(cè)量和監(jiān)視對(duì)確定這些聯(lián)系極為重要的工具。534Theyalsodevelopedtechniquesforgeneratingcoastaltopographytosimulatefuturewetlandchangesbasedonuncoveredlinkagesandsea-levelrisescenarios545Wetlandtypes

AprogressiveclassificationofamarshandforestsystemcombiningdatafromLandsatThematicMapper(TM),colorinfraredphotography,andERS-1satelliteradarwasdevelopedthatimprovedclassificationaccuracyandresultedinadetailedidentificationofdifferenceswithinanearlymonotypicblackmarshinFlorida.5結(jié)合從LandsatTM衛(wèi)星、彩色紅外照片、ERS-1衛(wèi)星雷達(dá)上獲取的數(shù)據(jù)，構(gòu)建了沼澤和森林體系的累進(jìn)分類，改進(jìn)了分類精度，導(dǎo)致佛羅里達(dá)州幾乎單一黑色的沼澤地中有差異地區(qū)的細(xì)致區(qū)分。555Thesetypesofimprovementsinclassifyingcoastallandcoversarenecessarybeforeanaccurateportrayalofthelinkbetweenvegetationcharacteristicsandhydrologycanbemade.566VegetationbiomassVegetationindexesrelatedtobiomassmeasuresweregeneratedfrompassivemicrowavedataandLandsatTMdata.TheopticalTMvegetationindexbasedonredandnear-infraredwavelengthsisprimarilylinkedtochangesingreenbiomass.576Themicrowavevegetationindexbasedonmeasuringenergyemittedat6cmand21cmmicrowavewavelengthsisprimarilyresponsivetothevegetationwatercontent.Theimagesarenoticeablysimilar.Ifthemicrowaveinstrumentprovestobeanadequateestimatorofbiomassinthesewetlands,amonitoringprogramcouldbedevelopedaroundthisall-weather,day-and-nightsensor.587MonitoringfloodingSatelliteradarwasusedtomaptidalflooding,acriticalcontrolofcoastalvegetationdistribution.Radarimagestakenduringatimeofnear-continuousrecordingsofgroundbas