You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither SPIE nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the SPIE website.
We introduce a maximum a posteriori (MAP) algorithm and a sparse learning via iterative minimization (SLIM)
algorithm to synthetic aperture radar (SAR) imaging. Both MAP and SLIM are sparse signal recovery algorithms
with excellent sidelobe suppression and high resolution properties. The former cyclically maximizes the a
posteriori probability density function for a given sparsity promoting prior, while the latter cyclically minimizes
a regularized least squares cost function. We show how MAP and SLIM can be adapted to the SAR imaging
application and used to enhance the image quality. We evaluate the performance of MAP and SLIM using the
simulated complex-valued backscattered data from a backhoe vehicle. The numerical results show that both MAP
and SLIM satisfactorily suppress the sidelobes and yield higher resolution than the conventional matched filter
or delay-and-sum (DAS) approach. MAP and SLIM outperform the widely used compressive sampling matching
pursuit (CoSaMP) algorithm, which requires the delicate choice of user parameters. Compared with the recently
developed iterative adaptive approach (IAA), MAP and SLIM are computationally more efficient, especially with
the help of fast Fourier transform (FFT). Also, the a posteriori distribution given by the algorithms provides us
with a basis for the analysis of the statistical properties of the SAR image pixels.