Laurence N Harnett

US Patent:

55550363, Sep 10, 1996

Filed:

Jan 26, 1995

Appl. No.:

8/381361

Inventors:

Laurence N. Harnett - San Pedro CA
Merit M. Shoucri - Manhattan Beach CA

Assignee:

TRW Inc. - Redondo Beach CA

International Classification:

G08G 100

US Classification:

340933

Abstract:

A passive millimeter traffic sensor sensing device for the direct detection of the movement or presence of vehicles within a predetermined field of view. The sensing device includes MMIC type sensing devices and heterodyne receivers, which include an antenna, local oscillator, mixer, a plurality of intermediate frequency amplifiers, a detector, and appropriate signal conditioning circuitry to detect signals in the millimeter wave region emanating from various objects such as motor vehicles, and also millimeter wave signals from the atmosphere reflected off of such objects. Thus, the sensing device detects the natural millimeter wave radiation coming from a scene. The intensity of the radiation is related to the effective radiometric temperatures in the scene which cause various objects, which have varying characteristics as both millimeter wave emitters and as reflectors, to appear as varying signal amplitudes to the sensing device. The sensing device may be mounted at a highway overpass or atop a light pole adjacent a highway and can provide information relating to the presence of a vehicle, whether moving or stationary, as well as the approximate length of the vehicle and approximate speed at which the vehicle travels through the sensing device's predetermined field of view.