Performance analysis and improvement of phase gradient autofocus algorithm

[1] Jakoatz C V, Wahl D E. Spotlight-mode synthetic aperture radar:a signal processing approach[M]. Boston:Kluwer Academic Publishers, 1996.221~222 [2]Wahl D E,Eichel P H,Ghiglia D C, et al. Phase gradient autofocus——a robust tool for high resolution SAR phase correcton[J]. IEEE Transactions on Aerospace and Electronic Systems, 1994,30(3):827~834 [3]Jakowatz C V,Wahl D E. Eigenvector method for maximum- likelihood estimation of phase errors in synthetic-aperture radar imagery [J]. Optical Society of America,1993,10(12):2539~2545 [4]Tsakalides P,Nikias C L. High-resolution autofocus techniques for SAR imaging based on fractional lower-order statistics[J]. IEEE Proceedings-Radar,Sonar and Navigation,2001,148(5):267~276