MM-band radiometric system for contraband detection applications

International passenger transportation by air, rail, automobile or sea transport is growing daily. One of the major tasks of the customs service is examination of passengers and their luggage for detection of foreign objects and prohibited substances, e.g. weapons, narcotic substances and illicit items. At customs luggage control, methods of both direct examination and automated examination equipment are widely used. However, current technical means do not go beyond applications of different types of metal detectors, which guarantee detection of hidden metal objects (weapons) on the human body, but cannot detect nonmetal objects, such as explosive and narcotic substances, or weapons made from ceramic materials. Due to their low absorption in fabric materials, millimeter band electromagnetic waves can serve for the customs service as an additional source of remotely obtained information concerning any relevant "discontinuities" located on a human body under clothes, and the dimensions and types of such discontinuities. These peculiarities could essentially reduce the number of persons subjected to additional personal control and, as a result, essentially raise efficiency of customs examination as a whole. Based on reception of a person's own heat radiation, the method of passive radiometric supervision is expected to have the best prospects, as it is not connected with generation in public places of additional high intensity electromagnetic fields, which may have negative effects on both inspected people and customs staff.