SAR image reconstruction by expectation maximization based matching pursuit
Date
2015Source Title
Digital Signal Processing: A Review Journal
Print ISSN
1051-2004
Publisher
Academic Press
Volume
37
Issue
1
Pages
75 - 84
Language
English
Type
ArticleItem Usage Stats
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Abstract
Synthetic Aperture Radar (SAR) provides high resolution images of terrain and target reflectivity. SAR systems are indispensable in many remote sensing applications. Phase errors due to uncompensated platform motion degrade resolution in reconstructed images. A multitude of autofocusing techniques has been proposed to estimate and correct phase errors in SAR images. Some autofocus techniques work as a post-processor on reconstructed images and some are integrated into the image reconstruction algorithms. Compressed Sensing (CS), as a relatively new theory, can be applied to sparse SAR image reconstruction especially in detection of strong targets. Autofocus can also be integrated into CS based SAR image reconstruction techniques. However, due to their high computational complexity, CS based techniques are not commonly used in practice. To improve efficiency of image reconstruction we propose a novel CS based SAR imaging technique which utilizes recently proposed Expectation Maximization based Matching Pursuit (EMMP) algorithm. EMMP algorithm is greedy and computationally less complex enabling fast SAR image reconstructions. The proposed EMMP based SAR image reconstruction technique also performs autofocus and image reconstruction simultaneously. Based on a variety of metrics, performance of the proposed EMMP based SAR image reconstruction technique is investigated. The obtained results show that the proposed technique provides high resolution images of sparse target scenes while performing highly accurate motion compensation.
Keywords
AutofocusCompressed sensing
Expectation maximization based matching
Pursuit algorithm
Algorithms
Channel estimation
Computational complexity
Errors
Image matching
Imaging techniques
Maximum principle
Motion compensation
Remote sensing
Synthetic aperture radar
Auto-focus
Autofocus techniques
Autofocusing techniques
Expectation - maximizations
High resolution image
Image reconstruction algorithm
Matching pursuit algorithms
Remote sensing applications
Image reconstruction