HYBRID ELECTRODYNAMIC MODEL OF RADAR SIGNAL SCATTERING BY TWO-LAYER VOLUME
The noncontact monitoring of soils from airborne is topical now. The using of simulation instead of field-tests is justified due to heavy expenses. Many methods are known for accurate or approximate calculations of electromagnetic fields (EMF), that scattered by multilayered structures. However, there has not been developed a generic approach up to now, for fast engineering calculation of radar signal parameters, reflected by layered structures with irregularities and rough boundaries in far field. In this paper a flexible simulation model is produced. The model is capable of impulse response computation for scattering from multilayered surface with irregularities. The object is not concentrated and incident wave is not plane in conditions of small distances. Therefore principles, acceptable for far field problem, can not be used for near field. The developed model is based on boundaries facet representation of space distributed multilayered object. The facet is presented by impedance triangle with known scattering parameters. Resulting EMF is calculated by summarizing of partial fields scattering on triangle facet taking in account phases and polarization of incident electromagnetic wave. The model is based on high-frequency method, and it provides high speed of computations for large area aims having any layers number and the boundaries roughness. The paper deals with results, obtained with the help of the developed model: normalized RSC for one-layer structure with rough surface for different average width of layer; verification by normalized RSC for two-layer structure; attenuation influence on RSC for two-layer structure; RSC for two-layer structure with rough surfaces.