关于地表反照率遥感反演的几个问题_王介民

:2004-07-25;:2004-08-28:(973)(G2000077908):(1937-),,,,王介民1,高　峰1,2(1.中国科学院寒区旱区环境与工程研究所,甘肃兰州　730000;2.中国科学院资源环境科学信息中心,甘肃兰州　730000)):分析了地表反照率对陆面辐射能收支以及区域和全球气候的影响,强调了地表反照率是遥感反演陆面参数时的第一重要参数,地表反照率或多波段遥感中不同谱段的地表反射率的准确反演常常是准确估算其它陆面参数如植被和土地利用/土地覆盖等状况的先决条件。在对当前关于反照率的概念及容易混淆的术语进行阐述和说明的基础上,简述了遥感反演地表反照率的步骤和主要难点的解决方法,进而对常用陆面过程模式计算地表反照率的过程作了分析,并将其结果与MODIS有关产品进行了比较,强调了遥感与陆面过程模式和气候模式的结合。:地表反照率;二向反射分布函数;地面能量收支;陆面过程模式;遥感:TP79:A:1004-0323(2004)05-0295-061　引　言,,,,,(albedo),,(0.3-4.0m),(spectralalbedo),(reflectance)()2　为什么把地表反照率称为遥感反演中的第一重要参数?,,/,,(Rn):Rn=RS(1-)+(RL-T4s)(1):RS,,RL,T4s,,-,Ts(1)(RnS),(RnL),1()1,,(RL=T4s)(1/5)RS(1-),,,0.15,195200410REMOTESENSINGTECHNOLOGYANDAPPLICATIONVol.19No.5Oct.20041()80%85%(0.10.18),,0.250.35,1/3(),0.9,0.4,0.2,,,,,,:Rn=G+H+LE(2):G,H,E,L,,G0.1Rn;(LE),,,,,,(2),,,,,,,,,,,,,,3　对地表反照率这一基本概念的理解为什么会产生混淆和困惑?,,(),,,();,,,Planaralbedo,Sphericalalbedo,Localalbedo,Globalalbedo,DHR(Directionalhemispherical)albedo,Bi-hemisphericalalbedo,Black-skyalbedo,White-skyalbedo,,EOS/MODISBlack-skyalbedo,29619,,BRDF30,,1,BRDF(R)(i,i)(v,v),(i,i)Li(i,i),(v,v)():Lv(v,v)=20/20Li(i,i)R(v,v;i,i)cosisinididi(3),(Ei)(Er):Ei=20/20Li(i,i)cosisinididi(4)Er=20/20Lv(v,v)cosvsinvdvdv(5),:ErEi(6),1,,(),:Ei=Lisuncosi(7)i,sun(4)(7):(i,i)=ErEi=20/20R(v,v;i,i)cosvsinvdvdv(8),(i,i),(8)R(BRDF),,,MODISBlack-skyalbedo,,()i0/2,,,MODISWhite-skyalbedo;BRDF,(,),,,,BRDF,,,1,2,BRDF,,EOS/MISR49,,,4　利用卫星遥感反演地表反照率的主要难点何在?,()()(3)(1)DN,,(Wm-2sr-1),,,(2)(TOA),2975:20,,,,6S,MODTRAN,ATCOR,;,(),EOS/MODIS,,(MOD-04,17),(MOD-05,1719),(MOD-09),,(3),(),,(2)BRDF,,10%BRDF,EOS/MODISMODISAmbrals(AlgorithmforMODISBidirectionalReflectanceAnisotropiesoftheLandSurface)RossLi,1:R(v,i,,)=fiso()+fvol()Kvol(v,i,,)+fgeo()Kgeo(v,i,,)(9)3(f),(K)KvolRossThick,;KgeoLiSparse,MODISR,,(9)3fiso,fvol,fgeo,Black-skybs3:bs(i,)=fiso()+fvol()hvol(i)+fgeo()Hgeo(i)=fiso()+fvol()(-0.007574-0.0709872i+0.3075883i)+fgeo()(-1.284909-0.1663142i+0.041803i)(10)White-skywsbsi:ws()=fiso()+0.189184fvol()-1.377622fgeo()(11)(i,)(i,)=(1-S)bs(i,)+Sws()(12):SSWhite-sky,(4),,AVHRR,(Liangetal,2000,2003,2)9,AVHRR,LandsatTM/ETM+,MODIS,,0.025　常用的陆面过程模式中反照率是如何处理的?是否可用卫星遥感产品取代?(GCMs),,;2060,SiB2(2),BATS(Biosphere-AtmosphereTransferScheme),OSULSM(OregonStateUniversityLandSurfaceModel),CLM(CommonLandModel),,,,,,,,29819CommonLandModel(NCARCCSM2CommunityLandModel,CLM2)40.7m,(0.7m)(0.7m),,:=sfs+snfsn+vfv(13)ssnv,f,ss=sat+min{sat,max[0.01(11-40M),0]}(14)CLM8,satM()s,0.7m0.7m2sn(,)iCLMi600.95(0.7m)0.65(0.7m)(fsn,s,)(fsn,v,/)v,(),/(LAI,SAI),,0.7m0.7m,CLM(LAI),SiB2,AVHRR(NDVI),,(IGBP18),;,MODIS,CLMMODISBRDF/Albedo(MOD43),1km,16d,3(0.30.7m,0.75.0m,0.33.0m)Black-skyWhite-skyQA(),CLMZhouetal(2003)52001MOD43B3CLM,,,MODIS,0.020.04,,CLM,CLM(0.30.7m)0.40.5,(0.75.0m)0.050.1CLM,/(LAI,SAI),,CLM,82;MODISBRDF/AlbedoCLM,CLM,,MODIS,,,,,,,AVHRRNDVI,,0.020.05,,MODIS,,6　结　语,2995:,,EOS/MODIS,MODISBRDF,16d1km,-(0.30.7m,0.75.0m,0.33.0m),,,MODISMODIS,/(LAI,SAI),0.40.5;,LAI/SAI,,,,AVHRRNDVI,,,(G2000077908):1,,,.M.:,2001.2YANGShunlin.QuantitativeRemoteSensingofLandSurfacesM.NewJersey:JohnWiley&Sons,Inc.,2004.3SchaafCB,GaoF,StrablerAH,etal.FirstOperationalBRDF,AlbedoNadirReflectanceProductsfromMODISJ.RemoteSenEnviron,2002,83:135148.4DaiY,ZhouL,DickinsonRE,etal.TheCommonLandModelJ.BullAmerMeterSoc,2003.10131023.5ZhouL.ComparisonofSeasonalandSpatialVariationsofAlbedosfromMODISandCommonLandModelJ.JGeophysResAtmosphere,2003,108(D15):4488.DiscussionontheProblemsonLandSurfaceAlbedoRetrievalbyRemoteSensingDataWANGJie-min1,GAOFeng1,2(1.ColdandAridRegionsEnvironmentalandEngineeringResearchInstitute,ChineseAcademyofSciences,Lanzhou730000,China;2.TheScientificInformationCentreforResourcesandEnvironment,ChineseAcademyofSicences,Lanzhou730000,China;)Abstract:Theeffectsofalbedoonlandsurfaceradiationbudgetandregionalandglobalclimatewereanalyzedinthispaper.Retrievingaccuratelylandsurfacealbedobyremotesensingdataisthepreconditionofotherlandsurfaceparametersretrieval,soalbedoisthefirstimportantparameterinlandsurfaceparametersretrievalbyremotesensingdata.Onthebasisoftheconceptofalbedoandothertermsoftenconfusedweredemonstrated,thestepsandsolutionstomaindifficultiesofretrievinglandsurfacealbedobyremotesensingdataweregivenanddiscussedbriefly.Atlast,weanalyzedtheprocessofcalculatingalbedoinpresentlandsurfaceprocessmodelsandcomparedtheresultswiththeproductsrelatedtoMODIS.Theintegrationofremotesensingandlandsurfaceprocessmodelsandglobalclimatemodelswasemphasized.Keywords:Landsurfacealbedo;BRDF;Landsurfaceradiationbudget;Landsurfaceprocessmodel;Remotesensing30019