Sparse representation-based algorithm for joint SAR image formation and autofocus

作者：Hasankhan Mohammad Javad; Samadi Sadegh^*; Cetin Mujdat

来源：Signal, Image and Video Processing, 2017, 11(4): 589-596.

DOI：10.1007/s11760-016-0998-y

• Synthetic aperture radar (SAR)
• Autofocus
• Sparse representation
• Synthesis dictionary
• Phase error

Inaccuracies in the observation model of the synthetic aperture radar (SAR) due to inaccuracies of the velocity and position of the platform or atmospheric turbulence cause degradations in reconstructed images which necessitate the use of autofocus algorithms. In this paper we propose a novel signal processing algorithm for joint SAR image formation and autofocus in a synthesis dictionary based sparse representation framework. Proposed algorithm can be applied broadly to scenes that exhibit sparsity with respect to any dictionary. This is done by extending our previously developed sparse representation-based SAR imaging framework to joint SAR image formation and autofocus. To this end, the phase error vector is separated from the unknown phase of the complexvalued back-scattered field. Phase error vector is estimated using a MAP estimator and compensated through an iterative algorithm to produce focused images. We demonstrate the effectiveness of the proposed approach on synthetic and real imagery.

• 出版日期2017-5