Patent ID: 8890745

Claim:
A method of detecting an object, the method comprising: receiving first reflected radio frequency (RF) signals from a region using an antenna; generating a first backscattering signature of the region from the first reflected RF signals; receiving second reflected RF signals from the region using the antenna subsequent to receiving the first reflected RF signals; generating at least one second backscattering signature of the region from the second reflected RF signals; determining whether the at least one second backscattering signature substantially matches a pre-determined backscattering signature associated with an object of interest from a library of pre-determined backscattering signatures; receiving third reflected RF signals from the region using the antenna subsequent to receiving the second reflected RF signals; generating a plurality of third backscattering signatures from the third reflected RF signals; determining whether the plurality of third backscattering signatures converge over time with respect to the pre-determined backscattering signature; detecting a difference between the first backscattering signature and the at least one second backscattering signature; and providing a warning indication in response to the difference between the first backscattering signature and the at least one second backscattering signature.