Near field Physical Optics modelling for Concealed Weapon Detection

A modelling technique is presented for simulating the received signal in a body scanner for concealed weapon detection (CWD) at millimeter wavelengths. The technique is based on a physical optics (PO) near field refinement and encompasses dielectric and perfect electric conductor (PEC) targets, thus reproducing the behaviour of human tissues and of possible concealed threats. Simulated data can be used for testing near field imaging algorithms without resorting to costly measurement experiments. In this communication the original far field formulation and the near field refinement are compared by using simulated data. The model is then validated using single and multi-frequency measured scattered fields by a metallic cylinder acquired in an anechoic chamber.