Contraband detection system

A method of detecting contraband, comprising the steps of:

• uniformly illuminating a field of view, within which are disposed objects or persons to be examined, with millimeter-wave radiation generated by sources of such radiation;
• modulating the amplitude of the radiation emitted by the sources;
• disposing a two-dimensional array of detectors sensitive to millimeter-wave radiation in a position such that radiation reflected from objects or persons in the field of view is incident thereon, each of said detectors providing an output signal responsive to said radiation reflected from objects or persons in a corresponding portion of the field of view;
• and
• forming an essentially real time image of the objects or persons within said field of view, responsive to illumination radiation reflected therefrom detected by the elements of the array,
• wherein the pixels of the image represent the radiation detected by the elements from the corresponding portions of the field of view.

Apparatus for detection of contraband, comprising:

• at least one two-dimensional array of spatially distributed point sources of millimeter wave radiation arranged to illuminate a field of view;
• means for focusing millimeter wave radiation from the field of view onto a focal plane;
• a two-dimensional staring array of detectors disposed in said focal plane, each of the detectors generating an output signal responsive to millimeter-wave radiation from a particular portion of the field of view,
• wherein said output signals of said detectors provide sufficient information for generating, essentially in real time, an image of the field of view such that the pixels of the image correspond to the output signals generated by the detectors of the array;
• and
• local oscillator means for providing a local oscillator signal to the array of detectors, whereby the detectors individually mix the local oscillator signal with the radiation received from the corresponding portion of the field of view.

Apparatus for detection of contraband, comprising:

• at least one two-dimensional array of spatially distributed point sources of millimeter wave radiation arranged to illuminate a filed of view,
• wherein the point sources of radiation comprise oscillators which do not resonate at the same frequency thereby providing a substantially incoherent illumination of the field of view;
• means for focusing millimeter wave radiation from the field of view onto a focal plane;
• and
• a two-dimensional staring array of detectors disposed in said focal plane, each of the detectors generating an output signal responsive to millimeter-wave radiation from a particular portion of the field of view,
• wherein said output signals of said detectors provide sufficient information for generating, essentially in real time, an image of the field of view such that the pixels of the image correspond to the output signals generated by the detectors of the array.

A method of detecting contraband, comprising the steps of:

• uniformly illuminating a field of view, within which are disposed objects or persons to be examined, with millimeter-wave radiation generated by a two-dimensional array of sources;
• disposing a two-dimensional array of detectors sensitive to millimeter-wave radiation in a position such that radiation reflected from objects or persons in the field of view is incident thereon, each of said detectors providing an output signal responsive to said radiation reflected from objects or persons in a corresponding portion of the field of view;
• providing a local oscillator signal to the array of detectors, which detectors individually mix the local oscillator signal with the radiation received from the corresponding portion of the field of view;
• and
• forming an essentially real time image of the objects or persons within said field of view, responsive to illumination radiation reflected therefrom detected by the elements of the array,
• wherein the pixels of the image represent the radiation detected by the elements from the corresponding portions of the field of view.