The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 02, 1994
Filed:
Apr. 09, 1992
Carter C Smith, San Diego, CA (US);
John B Gehman, La Jolla, CA (US);
Hughes Missile Systems Company, Los Angeles, CA (US);
Abstract
Method and arrangement for an airborne radar system particularly adapted to detect large metal targets that are concealed from the air by camouflage or natural foliage. The arrangement includes an antenna that transmits a continuous wave electromagnetic signal having a selectable frequency that preferably has a wave length generally twice the length of an anticipated target and which is carried by a flying vehicle. The frequency of the transmitted signal is chosen to provide maximum penetration of the camouflage or natural foliage and maximum re-radiation from a metal target. Receivers connected to an in-line receiving antenna and to a crossed receiving antenna carried by a flying vehicle detect the radiation that is reflected from the terrain and a target with the same polarization as that transmitted. The co-linear antenna and receiver respond to the reflected radiation while the cross-polarized antenna does not detect this reflected radiation. However, a metal object on the ground re-radiates cross polarized electromagnetic waves in proportion to their angular orientation and lateral distance to the transmitting antenna so that a metal target is detected by observing the output differences for the two receivers.