Abstract: Methods and apparatus for early detection and identification of a threat such as individuals carrying hidden explosive materials, land mines on roads, etc. are disclosed. One method comprises illuminating a target with radiation at a first polarization, collecting first radiation reflected from the target which has the same polarization as the first polarization, illuminating a target with radiation at a second polarization, and collecting second radiation reflected from the target which has the same polarization as the second polarization. A threat determination is then made based on the difference between the energy values of the first and second collected radiations. In other embodiments, the difference between energy values is used in conjunction with an evaluation of the returned energy in comparison with returned energy from other targets in order to additionally assess whether the primary target is a threat.

Abstract: Methods and Apparatus for early detection and identification of a threat, and alerting against detected threats, such as individuals wearing or carrying explosive materials and/or weapons, e.g., suicide bombers and other terrorists, at a great enough distance to limit loss of life and destruction of property are disclosed. The methods comprise transmitting a signal in the direction of a potential threat, measuring the detected reflected signal, and comparing the signal level with a threshold indicative of a threat. A monitor is employed to display the threat and attributes of the detected signals. The invention further illuminates the suspicious individual(s) with a Laser illuminator/designator and provides information about the distance to the suspicious individual(s).