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:
Mar. 12, 1991
Filed:
Mar. 29, 1990
Yoji G Niho, Rancho Palos Verdes, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
The present invention discloses an autofocusing method and apparatus for Synthetic Aperture Radar which employs operation on two or three subarrays of the SAR compressed data to estimate quadratic and cubic phase errors in the data. Focusing of the SAR array may then be accomplished by removing the estimated phase error from the data to sharpen the image. Phase error is estimated by FFT filtering product arrays formed by multiplying the complex conjugate of one subarray by another of the subarrays to form a correlation function. The correlation functions are integrated. A peak detection of the integrated correlation functions yields a peak location in the filter which is proportional to the phase error which may then be calculated.