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:
Dec. 29, 1998
Filed:
Apr. 28, 1997
Herbert C Stankwitz, Ann Arbor, MI (US);
Ken W Burgener, Ann Arbor, MI (US);
Erim International, Inc., Ann Arbor, MI (US);
Abstract
A high-order synthetic aperture radar (SAR) autofocusing method decomposes phase error into basis function components, one order at a time. Image patches are partitioned into a plurality of subapertures in accordance with positive- and negative-going slope of the basis function at each order. A positive mask is applied to each subaperture within which the basis function is increasing in slope, whereas a negative mask is applied to each subaperture within which the basis function is decreasing in slope. The results are then correlated to obtain a focused image, with the principle of map-drift preferably being used to compute phase-amplitude weights. The method may be uniformly applied, enabling the steps to be performed at a plurality of increasingly higher orders without performance degradation.