Optimal Sharpness Function for SAR Autofocus

Author

Schulz, Timothy J.

Author_Institution

Dept. of Electr. & Comput. Eng., Michigan Technol. Univ., Houghton, MI

Volume

14

Issue

1

fYear

2007

Firstpage

27

Lastpage

30

Abstract

Phase-error correction through the optimization of an image-domain sharpness function provides one method for the auto-focus of synthetic aperture radar (SAR) imagery. Several ad-hoc sharpness functions have been proposed, implemented, and analyzed, but none of these has been motivated as the solution to a well-defined statistical estimation problem. In this letter, a SAR sharpness function is derived that induces the solution to maximum-likelihood and maximum-posterior estimation for idealized SAR data. Furthermore, a limiting form of the optimal sharpness function is shown to be the popular intensity-squared sharpness

Keywords

error correction; error statistics; maximum likelihood estimation; radar imaging; synthetic aperture radar; SAR; autofocusing; image-domain sharpness function; intensity-squared sharpness; maximum-likelihood estimation; maximum-posterior estimation; optimization; phase-error correction; statistical estimation; synthetic aperture radar imagery; Computer errors; Discrete Fourier transforms; Error correction; Layout; Maximum likelihood estimation; Optimization methods; Phase estimation; Reflectivity; Signal processing; Synthetic aperture radar; MAP estimation; synthetic aperture radar (SAR);

fLanguage

English

Journal_Title

Signal Processing Letters, IEEE

Publisher

ieee

ISSN

1070-9908

Type

jour

DOI

10.1109/LSP.2006.881525

Filename

4035715