Electromagnetic simulator based on graphical computing and physical optics for sub-THz ISAR imagery of space objects

The paper proposes an implementation of the high-frequency technique for simulating the electromagnetic-wave reflectivity of electrically large objects at sub-THz frequencies, with the aim of producing ISAR images of space objects and building a database for automatic classification using semantic classifiers. A simulator has been built based on the graphical computer software Blender, which can provide precise and efficient ray-tracing calculation for geometrical optics (GO) implementation, and physical optics and impedance boundary conditions (PO -IBC) for wave effects computation. The simulator is capable to produce images which account for the frequency dependent effects, such sensitivity to surface roughness and materials' electrical properties. The results indicate that the tool has a great potential for fast generation of high-resolution images at extremely high frequencies where the computational load is only spent on the electromagnetic part and the ISAR processing, while the large amount of CPU required by the geometric manipulations of models for ray-tracing calculations are made with GPU accelerators.