Image reconstruction for EM penetration and interference

Complex aircraft structures, such as those of helicopters, are modeled using full-wave solvers of Maxwell's equations, such as the Finite-Difference Time-Domain method. Using these techniques, color images of penetrating electromagnetic fields inside a helicopter fuselage, primarily through the aircraft windshield which is electromagnetically transparent, are reconstructed. These images are color coded to represent the penetrating field intensity are used to identify potentially `host spots' within the airframe. These hot spots, of the reconstructed images of the penetrating electromagnetic field, can interfere with digital systems installed in the aircraft and can it cause a digital upset of the system. Selected examples of color coded images from penetrating electromagnetic fields inside the AII-64A Apache Helicopter are included. The level of the penetrating fields is function of the size and material of the windshield, as well as the incidence angle, frequency, and polarization of the electromagnetic wave.