1、12345678 43432121dFSdFSL dFSdFSLiririririririrrrrrrrrBLLdFS/LdFS/LRVIrirrrriririrrir2143 1RVI1RVINDVI 910irrPVI = R cos-RsinrirRRRVI rirrirRRRRNDVI irrPVI = (R -b)cos-Rsin11sinR-cosR = PVIrirARirRrPVI 为土壤线与为土壤线与Rr坐标轴之间的夹角。坐标轴之间的夹角。若忽略土壤线在若忽略土壤线在Rir轴上的截距,则轴上的截距,则A(Rr,Rir)的的PVI值实际值实际上就是上就是A点到土壤线的垂直距离。
2、点到土壤线的垂直距离。121314rirrirRRRRNDVI 15 为了解释背景的光学特征变化并修正为了解释背景的光学特征变化并修正NDVI对土壤对土壤背景的敏感,背景的敏感,Huete等(等(1998)提出了可适当描述土壤)提出了可适当描述土壤-植被系统的简单模型,即土壤调整植被指数(植被系统的简单模型,即土壤调整植被指数(SAVI-Soil Adjusted Vegetation Index),其表达式为:),其表达式为:161718192021EVI = 2.5*(NIR - Red) / (NIR + 6*Red - 7.5*Blue - 1) 2223 Leaf area inde
3、x (LAI) is ratio of the total area of all leaves on a plant to the area of ground covered by the plant. 242526ee, sLAIkLAIk,v,R)1(RR 2722M1Mins M11cos eeeer , sLAIkLAIkr,vrir, sLAIkLAIkir,virR)1(RR R)1(RRrririr )e1)(MRR(cossinRcosRPVIkLAIr,vir,vrir ,1ln1cos ()v irv rPVILAIkRMR 28eeLAIkr,vr, sr,vLAIk
4、ir,vir, sir,vrirrir)RR(R)RR(RRRRVI eeeeeeLAI)kk(LAIkLAI)kk(r, sir,vir, sLAIkrs,irv,LAIkr, sLAIkir,vir, sir,vrirrrirrrirCB RRRRR R)RR(RRVI (1)1 () ()()RVIBkrLAICkirkr LAIBCBkrC kirkr LAI29)exp(1 )exp(1 LAICBARVILAICBANDVI CBANDVILAI/ )/1ln( 3031323334SVRffRR)1 ( )()(1SVSRRRRf)()(2SVSf)()(3SVSNDVINDVINDVINDVIf)()(minmaxmin4NDVINDVINDVINDVIf3536373839404142