Numerical Study for Backscattering Enhancement of Concrete Specimens with FRP-TriCR Buried and Its Compatibility with Infrared Camouflage

Lower electromagnetic backscattering from concrete pavement as its smooth surface results the much darker image feature when exposures to imaging radar when compared with rough surface such as vegetation. In this paper, exploratory research on radar cross-section enhancement of concrete specimens with composite scatterer consisted of fiberglass reinforced plastics and trihedral corner reflector (FRP-TriCR) buried is presented. Scattering properties of concrete specimen, corner reflector, concrete specimen mixed with corner reflectors and with FRP-TriCR buried are numerical simulation based on the model of finite difference-time domain (FD-TD) in lossy dielectric with perfect matched layer (PML) in z-direction and period boundary conditions(PBC) in x,y-direction. In the conditions of given incident wave and dielectric coefficient of concrete specimen, the monostatic RCS of concrete specimen with FRP-TriCR buried is -5.6 dBsm and the average is -10.6 dBsm when theta is 30 to 60 degree, which increase much when compared to concrete specimen mixed trihedral corner reflector ( monostatic RCS is -12.3 dBsm, the average is -15.8 dBsm from theta = 30 to theta = 60 degree). It is much more important that FRP-TriCR scatterer is independence of moisture of concrete. On the other hand, the transmission characteristic of infrared radiation has been changed because of cavity structure, which is possible for compatibility for camouflage.