An Improved PFA With Aperture Accommodation for Widefield Spotlight SAR Imaging

Author

Bo Fan ; Yuliang Qin ; Peng You ; Hongqiang Wang

Author_Institution

Sch. of Electron. Sci. & Eng., Nat. Univ. of Defense Technol., Changsha, China

Volume

12

Issue

1

fYear

2015

fDate

Jan. 2015

Firstpage

3

Lastpage

7

Abstract

This letter presents an improved polar format algorithm for nonlinear aperture and widefield spotlight synthetic aperture radar imaging. In the proposed algorithm, the chirp $z$ transform is used for uniform range resampling, while the fast Gaussian grid nonuniform fast Fourier transform is employed to focus the nonuniform samples in azimuth. Additionally, the space-variant postfiltering is incorporated for eliminating the geometric distortion and marginal defocusing effects induced by wavefront curvature. The effectiveness of the proposed algorithm is validated by simulation and real large scene Gotcha data set.

Keywords

fast Fourier transforms; image sampling; radar imaging; radar polarimetry; synthetic aperture radar; Gaussian grid nonuniform fast Fourier transform; aperture accommodation; chirp z transform; geometric distortion; improved polar format algorithm; marginal defocusing effects; nonlinear aperture; nonuniform samples; real large scene Gotcha data set; space-variant postfiltering; uniform range resampling; wavefront curvature; widefield spotlight synthetic aperture radar imaging; Apertures; Azimuth; Imaging; Radar imaging; Radar polarimetry; Signal processing algorithms; Synthetic aperture radar; Chirp $z$ transform (CZT); Chirp z transform (CZT); fast Gaussian grid nonuniform fast Fourier transform (FGG NUFFT); polar format algorithm (PFA);

fLanguage

English

Journal_Title

Geoscience and Remote Sensing Letters, IEEE

Publisher

ieee

ISSN

1545-598X

Type

jour

DOI

10.1109/LGRS.2014.2322858

Filename

6853358