Research On Spectral Simulation And Validation Of Winter Wheat By Remote Sensing Based On MSCOPE Model

The feature of vertical canopy heterogeneity or canopy distribution from the top to the bottom are of great significance for remote sensing diagnosis and monitoring of nutrient,disease and yield.Accurate spectral monitoring and authenticate of regional grain crops in due course is conducive to rational deployment of water and fertilizer plans and guidance of planting structure adjustment.The investigations and researches of crop spectrum with remote sensing science have become consequent study orientations for the last couple of years.However,the above studies are not comprehensive,so this paper conducts experiments from three levels:simulation,verification and application.Moreover,the effects of different structures and input physicochemical parameters of the m SCOPE（Soil Canopy Observation,Photochemistry and Energy Fluxes）model on the spectra of winter wheat were studied.A problem in the simulation is that the interaction between the photon and the blade internal is a complex scattering absorption process which can be explained by the radiation transfer equation.However,the complex and non-Lambertian structure of the blade makes the solution difficult.The solution is to simplify the blade structure and use statistical method to explain it.In this study,the leaves were stratified,and the light absorption,reflection and transmittance were modeled by the difference in leaf height to establish the stratified model of large leaves in the canopy,so as to realize parameter inversion of different layers and the whole canopy from the local to the whole canopy,supply seasonable spectral messages and direct the use of accurate farming.The purpose of this study is to explore the method of using the model to simulate winter wheat spectrum and verify and analyze its rationality from multiple perspectives.The chief research work is as follows:the first place is the preparatory phase before trying the experimentation.Here is the plan section.（1）Control variables only change the number of strata while other parameters remain unchanged.Perform preliminary experiments to select the appropriate number of strata.（2）To further verify the rationality of the model and parameter selection,the FAST algorithm in Simlab2.2 is applied to perform sensitivity analysis and quantitative analysis of the factors that have the deepest impact on the m SCOPE model.（3）The effective vegetation index is selected for subsequent spectral analysis by consulting the literature and empirical judgment.The second step of the formal experiment is divided into three levels:（1）In the simulation experiment,the spectrum concerned with the internal physiological structure elements and the mechanism research was dissected based on the spectrum metadata gived birth by the m SCOPE simulation.（2）In the verification experiment,use real spectral data and simulated data to develop statistical indicators to evaluate the accuracy of inverted vegetation indices（VIs）.（3）In the application experiment,the nitrogen index is calculated for farmland fertilization guidance and nutrient planning through the experimental analysis of disparate nitrogen swatches.The emulation outcomes show that the runing workpiece ratio of winter wheat canopy is 127.43 when the canopy is divided into three layers,which is much higher than other layers.Simultaneously,the simulation results also prove that the vertical distribution of parameters has different effects on canopy reflectance of characteristic bands as follows:the leaf area index（LAI）has effects on almost all bands;the chlorophyll content(₍（6（7））mainly affects the visible region,while the water content()only affects the near-infrared region.The validation results showed that the selection of vegetation indices in different bands was significantly related to the agronomic parameters of the canopy.、₍(6（7） andaffected the estimation of vegetation indices related to them,respectively.It is worth mentioning that the RMSE of the new vegetation index(1₂0)0)9))proposed by us is the smallest,which is0.042.Sensitivity analysis showed that the spectrum was more sensitive to the change of upper parameters,which verified the rationality of the MSCOPE model to explain the law that the breakthough power of light whittled increasingly with the layers up in the vertical non-uniform canopy.