Comparison of synthetic-aperture radar autofocus techniques: phase gradient versus subaperture

TM Calloway, CV Jakowatz Jr… - Advanced Signal …, 1991 - spiedigitallibrary.org
Two methods of focusing synthetic aperture radar (SAR) images are compared. Both a
conventional subaperture cross-correlation method and a new phase gradient autofocus …

Range dependent phase gradient autofocus

DG Thompson, JS Bates, DV Arnold… - IGARSS'98. Sensing …, 1998 - ieeexplore.ieee.org
The Phase Gradient Autofocus (PGA) algorithm has been widely used in spotlight synthetic
aperture radar (SAR) to remove motion-induced blurs in the images. The PGA algorithm has …

Extending the phase gradient autofocus algorithm for low-altitude stripmap mode SAR

DG Thompson, JS Bates… - Proceedings of the 1999 …, 1999 - ieeexplore.ieee.org
The phase gradient autofocus (PGA) algorithm has been widely used in spotlight synthetic
aperture radar (SAR) to remove motion-induced blurs in the images. The PGA algorithm has …

Phase gradient autofocus-a robust tool for high resolution SAR phase correction

DE Wahl, PH Eichel, DC Ghiglia… - IEEE Transactions on …, 1994 - ieeexplore.ieee.org
The phase gradient autofocus (PGA) technique for phase error correction of spotlight mode
synthetic aperture radar (SAR) imagery is examined carefully in the context of four …

An investigation of synthetic aperture radar autofocus

IP Finley, JW Wood - NASA STI/Recon Technical Report N, 1985 - ui.adsabs.harvard.edu
The principles of SAR and the requirement for an autofocus system are discussed. Three
autofocus methods are investigated: measurement of the power spectrum, constrast …

Multichannel autofocus algorithm for synthetic aperture radar

RL Morrison, MN Do - 2006 International Conference on Image …, 2006 - ieeexplore.ieee.org
The autofocus problem in synthetic aperture radar (SAR) is considered, where phase errors
in the acquired signal data result in imagery that is improperly focused. We present a new …

Subaperture autofocus for synthetic aperture radar

TM Calloway, GW Donohoe - IEEE Transactions on Aerospace …, 1994 - ieeexplore.ieee.org
A subaperture autofocus algorithm for synthetic aperture radar (SAR) partitions range-
compressed phase-history data collected over a full aperture into equal-width subapertures …

Applications of phase gradient autofocus to aperture synthesis imaging

PH Eichel, DC Ghiglia, CV Jakowatz… - Sixth …, 1989 - ieeexplore.ieee.org
Summary form only given. A recently developed synthetic aperture radar (SAR) autofocus
technique called the phase gradient autofocus (PGA) algorithm is considered. it has been …

New autofocus technique for wideband wide-angle synthetic aperture radar

D Kirk, P Maloney - … for Synthetic Aperture Radar Imagery V, 1998 - spiedigitallibrary.org
A small difference between the true range to the scatterer and that estimated from the radar
time delay results in defocusing of Synthetic Aperture Radar (SAR) imagery in both cross …

Synthetic-aperture radar autofocus by maximizing sharpness

JR Fienup - Optics letters, 2000 - opg.optica.org
To focus a synthetic-aperture radar image that is suffering from phase errors, a phase-error
estimate is found that, when it is applied, maximizes the sharpness of the image. Closed …