Modeling and simulation of the emissivity of vegetation using passive remote sensing methods

Abstract

Remote sensing is a scientific technique to acquire characteristics of object with out physical contact. Gravitational, magnetic, optical and electrostatic forces and resulting actions are sources for remote sensors. Electromagnetic radiation that is emitted or reflected by the object carries specific properties about object. The ef fect of object on the gathered wave is investigated and some unique properties of the object is obtained with this remote sensing process. To be able to sense complex struc tures, the structure should be modeled as a familiar geometry. In this thesis, modeling of vegetation and calculated absorption cross section and emissivity simulation was studied. Emissivity is one of frequently used remote sensing parameter for objects. In literature, remote sensing of vegetation includes different methods that are based on measurements with active remote sensing. In this study, vegetation components were considered separately that leaves were modeled as dielectric disks and branches and trunks were modeled as cylinders. Emissivity and absorption cross section equa tions of geometrically facilitated vegetation was found out using two approximations. Emissivity for leaves was calculated using physical optics approximation on disk. In branches and trunks, infinite length approximation was applied on cylinder. To check the accuracy of equations and MATLAB calculations, absorption cross section calcu lation results were compared with literature studies on that of vegetation, and good agreement was found. Equations were simulated for frequency, dimensions, angle of incidence, and permittivity. In conclusion, vegetation was geometrically modeled, ab sorption cross section and emissivity equations were found. Emissivity and absorption cross section were simulated and effects of each parameter was examined.