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:
Apr. 30, 1996
Filed:
Feb. 16, 1995
Yuji Osawa, Tokyo, JP;
Toshihiro Sezai, Tokyo, JP;
National Space Development Agency of Japan, Tokyo, JP;
Abstract
An active reflector including an antenna, a frequency converter, and a delay circuit is placed at a location within an area to be detected by a synthetic aperture radar. The active reflector receives an incoming radio wave emitted by the synthetic aperture radar and changes its frequency or delay time. The resultant radio wave is transmitted as a reflected radio wave toward the synthetic aperture radar. As a result, the position of the active reflector image displayed on the screen of the synthetic aperture radar is shifted. The ambiguity is quantitatively detected from the pixel value at the original display position at which the active reflector image was displayed before it was shifted, thereby evaluating the image quality of the synthetic aperture radar.