Surveillance through concrete walls

This paper studies the capability of ultra-wideband short-pulse (UWB SP) radar to provide surveillance through concrete walls, including multistatic radar surveillance and 3D through-wall imaging. A full-wave electromagnetic simulator is used to generate high fidelity through-wall radar data. The raw radar data are transformed into radar images using a back projection algorithm. It is shown that UWB SP radar can track targets moving inside a room with concrete walls as well as providing static mapping of the room interior. The velocity of the electromagnetic wave inside a concrete wall is reduced compared to free space thus defocusing target images, displacing targets from their true positions, and possibly producing false targets. This problem can be mitigated by including the time of flight difference due to the concrete walls into the image generation algorithm. 3D through-wall radar imaging obtained using UWB SP radar centered at 2 GHz requires a very large antenna aperture to be able to see the shape of the human phantoms. However, using, a center frequency of 10 GHz reduces this aperture requirement fivefold making the system more practical operationally. However, attenuation is much higher at 10 GHz than at 2 GHz.