High-frequency Analysis Of Scattering From Complex Targets In Half Space

Today's complex, the varied electromagnetic environment on the battlefield radar system performance, environmental electromagnetic scattering analysis and concealed target detection and identification methods has ever-increasing demands. Electromagnetic environment in the complex and ever-changing, because of the interaction between the target and the environment, background and objectives to the surface of the complex scattering and radiation, For example, the sea of low-flying missiles, the forest vegetation cover, such as military targets, make the target of the modulation effect of the incident electromagnetic wave with the goal of independence exists is very different from the modulation effects. Therefore, there is the important theoretical value and military applications as battlefield environment to carry out the different objectives of the electromagnetic scattering.In this paper, the specific work and innovation include the following:1. In high-frequency area, the complex targets can be calculated with GRECO method, and the objectives of the edge diffraction and surface scattering can be calculated with the physical optics (PO) method and the equivalent electromagnetic method (MEC), then the results of RCS of complex targets is forecast; Based on this, the calculations of metal surfaces coated with radar absorbing materials is computed by the equivalent transmission line. From the electromagnetic field integral equation, the media, coating targets can be considered. In the end, the metal, dielectric, coating the mixed target can be consideded by the same way.2. Focus on analysis of electromagnetic scattering media, we made use of the traditional surface integration method for inhomogeneous media to computer the medium before, and now the Born and Rytov approximation have been introduced based on the Volume integral equation, then the analysis of the weak scattering medium is considered.3. For the past physical optical methods overlooked the current impact of shadow zone and led to the increasing problems of the large angle bistatic calculation, the improved method is deduced by introducing the improved current marching technique into conventional PO method. Combined with the graphical-electromagnetic computing method that extracted the illuminated and shadow facet in accordance with the direction of the incident sort iteration, we can spend less time calculating the bistatic radar cross-section of a conductive targets object.4. In order to consider the scattering fields of the electrically large PEC targets in half space, the half-space Green's function was introduced into the conventional method of physical optics (PO), method of equivalent currents (MEC). Combined with the graphical-electromagnetic computing (GRECO) method, the shadow regions are eliminated quickly by displaying lists technology of OpenGL to rebuild the target, and the geometry information is attained by reading the color and depths of each pixel. Finally, a ray-tracing technique is applied to each selected facet to compute the phase delay due to multiple bounce between the targets and the land. The results show that the method is efficient and accurate. Basis on this, the medium, coating targets in half space can be analysised by the impedance boundary conditions in the same way.